bool Window::IsIncluded(double left, double right) const
{
SpiceCell cellCopy = cell;
SpiceBoolean isIncluded = wnincd_c(left, right, &cellCopy);
if(failed_c())
CSpiceUtil::SignalError("Include test failed");
return isIncluded != SPICEFALSE;
}
void spice::eph_impl(double mjd2000, array3D &r, array3D &v) const{
SpiceDouble spice_epoch = kep_toolbox::util::epoch_to_spice(mjd2000);
spkezr_c ( m_target.c_str(), spice_epoch, m_reference_frame.c_str(), m_aberrations.c_str(), m_observer.c_str(), m_state, &m_lt );
r[0] = m_state[0] * 1000; r[1] = m_state[1] * 1000; r[2] = m_state[2] * 1000;
v[0] = m_state[3] * 1000; v[1] = m_state[4] * 1000; v[2] = m_state[5] * 1000;
/// Handling errors
if (failed_c()) {
std::ostringstream msg;
msg << "SPICE cannot compute the ephemerides, have you loaded all needed Kernel files?" << std::endl;
reset_c();
throw_value_error(msg.str());
}
}
bool spice_error(int error_detail) {
SpiceInt buffer_size = 1024;
char error_message[buffer_size];
if (failed_c()) {
switch(error_detail) {
case ALL :
//TODO: Neat way to concat all error messages.
//reset_c();
break;
case SHORT :
getmsg_c("SHORT", buffer_size, error_message);
reset_c();
rb_raise(rb_spice_error, "%s\n", error_message);
break;
case LONG :
getmsg_c("LONG", buffer_size, error_message);
reset_c();
rb_raise(rb_spice_error, "%s\n", error_message);
break;
case EXPLAIN :
getmsg_c("EXPLAIN", buffer_size, error_message);
reset_c();
rb_raise(rb_spice_error, "%s\n", error_message);
break;
default :
reset_c();
break;
}
}
return false;
}
void union_c ( SpiceCell * a,
SpiceCell * b,
SpiceCell * c )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
a I First input set.
b I Second input set.
c O Union of a and b.
-Detailed_Input
a is a CSPICE set. a must be declared as a SpiceCell
of data type character, double precision, or integer.
b is a CSPICE set, distinct from a. b must have the
same data type as a.
-Detailed_Output
c is a CSPICE set, distinct from sets a and b, which
contains the union of a and b (that is, all of
the elements which are in a or b or both). c must
have the same data type as a and b.
When comparing elements of character sets, this routine
ignores trailing blanks. Trailing blanks will be
trimmed from the members of the output set c.
-Parameters
None.
-Exceptions
1) If the input set arguments don't have identical data types,
the error SPICE(TYPEMISMATCH) is signaled.
2) If the union of the two sets contains more elements than can be
contained in the output set, the error SPICE(SETEXCESS) is signaled.
3) If the set arguments have character type and the length of the
elements of the output set is less than the maximum of the
lengths of the elements of the input sets, the error
SPICE(ELEMENTSTOOSHORT) is signaled.
4) If either of the input arguments may be unordered or contain
duplicates, the error SPICE(NOTASET) is signaled.
-Files
None.
-Particulars
This is a generic CSPICE set routine; it operates on sets of any
supported data type.
The union of two sets contains every element which is
in the first set, or in the second set, or in both sets.
{a,b} union {c,d} = {a,b,c,d}
{a,b,c} {b,c,d} {a,b,c,d}
{a,b,c,d} {} {a,b,c,d}
{} {a,b,c,d} {a,b,c,d}
{} {} {}
-Examples
1) The following code fragment places the union of the character sets
planets and asteroids into the character set result.
#include "SpiceUsr.h"
.
.
.
/.
Declare the sets with string length NAMLEN and with maximum
number of elements MAXSIZ.
./
SPICECHAR_CELL ( planets, MAXSIZ, NAMLEN );
SPICECHAR_CELL ( asteroids, MAXSIZ, NAMLEN );
SPICECHAR_CELL ( result, MAXSIZ, NAMLEN );
.
.
.
/.
Compute the union.
./
union_c ( &planets, &asteroids, &result );
2) Repeat example #1, this time using integer sets containing
ID codes of the bodies of interest.
#include "SpiceUsr.h"
.
.
.
/.
Declare the sets with maximum number of elements MAXSIZ.
./
SPICEINT_CELL ( planets, MAXSIZ );
SPICEINT_CELL ( asteroids, MAXSIZ );
SPICEINT_CELL ( result, MAXSIZ );
.
.
.
/.
Compute the union.
./
union_c ( &planets, &asteroids, &result );
3) Construct a set containing the periapse and apoapse TDB epochs
of an orbiter, given two separate sets containing the epochs of
those events.
#include "SpiceUsr.h"
.
.
.
/.
Declare the sets with maximum number of elements MAXSIZ.
./
SPICEDOUBLE_CELL ( periapse, MAXSIZ );
SPICEDOUBLE_CELL ( apoapse, MAXSIZ );
SPICEDOUBLE_CELL ( result, MAXSIZ );
.
.
.
/.
Compute the union.
./
union_c ( &periapse, &apoapse, &result );
-Restrictions
1) The output set must be distinct from both of the input sets.
For example, the following calls are invalid.
union_c ( ¤t, &new, ¤t );
union_c ( &new, ¤t, ¤t );
In each of the examples above, whether or not the subroutine
signals an error, the results will almost certainly be wrong.
Nearly the same effect can be achieved, however, by placing the
result into a temporary set, which is immediately copied back
into one of the input sets, as shown below.
union_c ( ¤t, &new, &temp );
copy_c ( &temp, &new );
2) String comparisons performed by this routine are Fortran-style:
trailing blanks in the input sets are ignored. This gives
consistent behavior with CSPICE code generated by the f2c
translator, as well as with the Fortran SPICE Toolkit.
Note that this behavior is not identical to that of the ANSI
C library functions strcmp and strncmp.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
C.A. Curzon (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
-Version
-CSPICE Version 1.1.0, 15-FEB-2005 (NJB)
Bug fix: loop bound changed from 2 to 3 in loop used
to free dynamically allocated arrays.
-CSPICE Version 1.0.0, 08-AUG-2002 (NJB) (CAC) (WLT) (IMU)
-Index_Entries
union of two sets
-&
*/
{ /* Begin union_c */
/*
Local variables
*/
SpiceChar * fCell[3];
SpiceInt fLen [3];
SpiceInt i;
/*
Standard SPICE error handling.
*/
if ( return_c() )
{
return;
}
chkin_c ( "union_c" );
/*
Make sure data types match.
*/
CELLMATCH3 ( CHK_STANDARD, "union_c", a, b, c );
/*
Make sure the input cells are sets.
*/
CELLISSETCHK2 ( CHK_STANDARD, "union_c", a, b );
/*
Initialize the cells if necessary.
*/
CELLINIT3 ( a, b, c );
/*
Call the union routine appropriate for the data type of the cells.
*/
if ( a->dtype == SPICE_CHR )
{
/*
Construct Fortran-style sets suitable for passing to unionc_.
*/
C2F_MAP_CELL3 ( "",
a, fCell, fLen,
b, fCell+1, fLen+1,
c, fCell+2, fLen+2 );
if ( failed_c() )
{
chkout_c ( "union_c" );
return;
}
unionc_ ( (char * ) fCell[0],
(char * ) fCell[1],
(char * ) fCell[2],
(ftnlen ) fLen[0],
(ftnlen ) fLen[1],
(ftnlen ) fLen[2] );
/*
Map the union back to a C style cell.
*/
F2C_MAP_CELL ( fCell[2], fLen[2], c );
/*
We're done with the dynamically allocated Fortran-style arrays.
*/
for ( i = 0; i < 3; i++ )
{
free ( fCell[i] );
}
}
else if ( a->dtype == SPICE_DP )
{
uniond_ ( (doublereal * ) (a->base),
(doublereal * ) (b->base),
(doublereal * ) (c->base) );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, c );
}
}
else if ( a->dtype == SPICE_INT )
{
unioni_ ( (integer * ) (a->base),
(integer * ) (b->base),
(integer * ) (c->base) );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, c );
}
}
else
{
setmsg_c ( "Cell a contains unrecognized data type code #." );
errint_c ( "#", (SpiceInt) (a->dtype) );
sigerr_c ( "SPICE(NOTSUPPORTED)" );
chkout_c ( "union_c" );
return;
}
/*
Indicate the result is a set.
*/
c->isSet = SPICETRUE;
chkout_c ( "union_c" );
} /* End union_c */
void gfrr_c ( ConstSpiceChar * target,
ConstSpiceChar * abcorr,
ConstSpiceChar * obsrvr,
ConstSpiceChar * relate,
SpiceDouble refval,
SpiceDouble adjust,
SpiceDouble step,
SpiceInt nintvls,
SpiceCell * cnfine,
SpiceCell * result )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
SPICE_GF_CNVTOL P Convergence tolerance
target I Name of the target body.
abcorr I Aberration correction flag.
obsrvr I Name of the observing body.
relate I Relational operator.
refval I Reference value.
adjust I Adjustment value for absolute extrema searches.
step I Step size used for locating extrema and roots.
nintvls I Workspace window interval count.
cnfine I-O SPICE window to which the search is confined.
result O SPICE window containing results.
-Detailed_Input
target is the name of a target body. The target body is
an ephemeris object; its trajectory is given by
SPK data.
The string `target' is case-insensitive, and leading
and trailing blanks in `target' are not significant.
Optionally, you may supply a string containing the
integer ID code for the object. For example both
"MOON" and "301" are legitimate strings that indicate
the Moon is the target body.
The target and observer define a position vector which
points from the observer to the target; the time derivative
length of this vector is the "range rate" that serves as
the subject of the search performed by this routine.
abcorr indicates the aberration corrections to be applied to
the observer-target state vector to account for
one-way light time and stellar aberration.
Any aberration correction accepted by the SPICE
routine spkezr_c is accepted here. See the header
of spkezr_c for a detailed description of the
aberration correction options. For convenience,
the options are listed below:
"NONE" Apply no correction.
"LT" "Reception" case: correct for
one-way light time using a Newtonian
formulation.
"LT+S" "Reception" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
"CN" "Reception" case: converged
Newtonian light time correction.
"CN+S" "Reception" case: converged
Newtonian light time and stellar
aberration corrections.
"XLT" "Transmission" case: correct for
one-way light time using a Newtonian
formulation.
"XLT+S" "Transmission" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
"XCN" "Transmission" case: converged
Newtonian light time correction.
"XCN+S" "Transmission" case: converged
Newtonian light time and stellar
aberration corrections.
Case and blanks are not significant in the string
`abcorr'.
obsrvr is the name of the observing body. The observing body is
an ephemeris object; its trajectory is given by SPK
data. `obsrvr' is case-insensitive, and leading and
trailing blanks in `obsrvr' are not significant.
Optionally, you may supply a string containing the
integer ID code for the object. For example both "MOON"
and "301" are legitimate strings that indicate the Moon
is the observer.
relate is a relational operator used to define a constraint
on observer-target range rate. The result window found
by this routine indicates the time intervals where
the constraint is satisfied. Supported values of
`relate' and corresponding meanings are shown below:
">" Distance is greater than the reference
value `refval'.
"=" Distance is equal to the reference
value `refval'.
"<" Distance is less than the reference
value `refval'.
"ABSMAX" Distance is at an absolute maximum.
"ABSMIN" Distance is at an absolute minimum.
"LOCMAX" Distance is at a local maximum.
"LOCMIN" Distance is at a local minimum.
The caller may indicate that the region of interest
is the set of time intervals where the quantity is
within a specified distance of an absolute extremum.
The argument `adjust' (described below) is used to
specify this distance.
Local extrema are considered to exist only in the
interiors of the intervals comprising the confinement
window: a local extremum cannot exist at a boundary
point of the confinement window.
Case is not significant in the string `relate'.
refval is the reference value used together with the argument
`relate' to define an equality or inequality to be
satisfied by the range rate between the specified target
and observer. See the discussion of `relate' above for
further information.
The units of `refval' are km/sec.
adjust is a parameter used to modify searches for absolute
extrema: when `relate' is set to "ABSMAX" or "ABSMIN" and
`adjust' is set to a positive value, gfdist_c will find
times when the observer-target range rate is within
`adjust' km/sec of the specified extreme value.
If `adjust' is non-zero and a search for an absolute
minimum `min' is performed, the result window contains
time intervals when the observer-target range rate has
values between `min' and min+adjust.
If the search is for an absolute maximum `max', the
corresponding range is from max-adjust to `max'.
`adjust' is not used for searches for local extrema,
equality or inequality conditions.
step is the step size to be used in the search. `step' must
be short enough for a search using this step size
to locate the time intervals where the specified
range rate function is monotone increasing or
decreasing. However, `step' must not be *too* short, or
the search will take an unreasonable amount of time.
The choice of `step' affects the completeness but not
the precision of solutions found by this routine; the
precision is controlled by the convergence tolerance.
See the discussion of the parameter SPICE_GF_CNVTOL for
details.
`step' has units of TDB seconds.
nintvls is a parameter specifying the number of intervals that
can be accommodated by each of the dynamically allocated
windows used internally by this routine. `nintvls' should
be at least as large as the number of intervals within
the search region on which the specified range rate
function is monotone increasing or decreasing. See
the Examples section below for code examples illustrating
the use of this parameter.
cnfine is a SPICE window that confines the time period over
which the specified search is conducted. `cnfine' may
consist of a single interval or a collection of
intervals.
In some cases the confinement window can be used to
greatly reduce the time period that must be searched
for the desired solution. See the Particulars section
below for further discussion.
See the Examples section below for a code example
that shows how to create a confinement window.
-Detailed_Output
cnfine is the input confinement window, updated if necessary
so the control area of its data array indicates the
window's size and cardinality. The window data are
unchanged.
result is the window of intervals, contained within the
confinement window `cnfine', on which the specified
constraint is satisfied.
If `result' is non-empty on input, its contents will be
discarded before 'gfrr_c' conducts its search.
`result' must be declared with sufficient size to capture
the full set of time intervals within the search region
on which the specified constraint is satisfied.
If the search is for local extrema, or for absolute
extrema with `adjust' set to zero, then normally each
interval of `result' will be a singleton: the left and
right endpoints of each interval will be identical.
If no times within the confinement window satisfy the
constraint, `result' will be returned with a cardinality
of zero.
-Parameters
SPICE_GF_CNVTOL
is the convergence tolerance used for finding endpoints
of the intervals comprising the result window.
SPICE_GF_CNVTOL is used to determine when binary searches
for roots should terminate: when a root is bracketed
within an interval of length SPICE_GF_CNVTOL, the root is
considered to have been found.
The accuracy, as opposed to precision, of roots found
by this routine depends on the accuracy of the input
data. In most cases, the accuracy of solutions will be
inferior to their precision.
SPICE_GF_CNVTOL is declared in the header file SpiceGF.h.
-Exceptions
1) In order for this routine to produce correct results,
the step size must be appropriate for the problem at hand.
Step sizes that are too large may cause this routine to miss
roots; step sizes that are too small may cause this routine
to run unacceptably slowly and in some cases, find spurious
roots.
This routine does not diagnose invalid step sizes, except
that if the step size is non-positive, an error is signaled
by a routine in the call tree of this routine.
2) Due to numerical errors, in particular,
- Truncation error in time values
- Finite tolerance value
- Errors in computed geometric quantities
it is *normal* for the condition of interest to not always be
satisfied near the endpoints of the intervals comprising the
result window.
The result window may need to be contracted slightly by the
caller to achieve desired results. The SPICE window routine
wncond_c can be used to contract the result window.
3) If an error (typically cell overflow) occurs while performing
window arithmetic, the error will be diagnosed by a routine
in the call tree of this routine.
4) If the relational operator `relate' is not recognized, an
error is signaled by a routine in the call tree of this
routine.
5) If the aberration correction specifier contains an
unrecognized value, an error is signaled by a routine in the
call tree of this routine.
6) If 'adjust' is negative, the error SPICE(VALUEOUTOFRANGE) will
signal from a routine in the call tree of this routine.
A non-zero value for 'adjust' when 'relate' has any value other than
"ABSMIN" or "ABSMAX" causes the error SPICE(INVALIDVALUE) to
signal from a routine in the call tree of this routine.
7) If either of the input body names do not map to NAIF ID
codes, an error is signaled by a routine in the call tree of
this routine.
8) If required ephemerides or other kernel data are not
available, an error is signaled by a routine in the call tree
of this routine.
9) If the workspace interval count is less than 1, the error
SPICE(VALUEOUTOFRANGE) will be signaled.
10) If the required amount of workspace memory cannot be
allocated, the error SPICE(MALLOCFAILURE) will be
signaled.
11) If any input string argument pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
12) If any input string argument is empty, the error
SPICE(EMPTYSTRING) will be signaled.
13) If either input cell has type other than SpiceDouble,
the error SPICE(TYPEMISMATCH) is signaled.
-Files
Appropriate kernels must be loaded by the calling program before
this routine is called.
The following data are required:
- SPK data: ephemeris data for target and observer for the
time period defined by the confinement window must be
loaded. If aberration corrections are used, the states of
target and observer relative to the solar system barycenter
must be calculable from the available ephemeris data.
Typically ephemeris data are made available by loading one
or more SPK files via furnsh_c.
In all cases, kernel data are normally loaded once per program
run, NOT every time this routine is called.
-Particulars
This routine determines if the caller-specified constraint condition
on the geometric event (range rate) is satisfied for any time intervals
within the confinement window 'cnfine'. If one or more such time
intervals exist, those intervals are added to the 'result' window.
This routine provides a simpler, but less flexible interface
than does the routine gfevnt_c for conducting the searches for
observer-target range rate value events. Applications that require
support for progress reporting, interrupt handling, non-default step
or refinement functions, or non-default convergence tolerance should
call gfevnt_c rather than this routine.
Below we discuss in greater detail aspects of this routine's
solution process that are relevant to correct and efficient
use of this routine in user applications.
The Search Process
==================
Regardless of the type of constraint selected by the caller, this
routine starts the search for solutions by determining the time
periods, within the confinement window, over which the specified
range rate function is monotone increasing and monotone decreasing.
Each of these time periods is represented by a SPICE window. Having
found these windows, all of the range rate function's local extrema
within the confinement window are known. Absolute extrema then can
be found very easily.
Within any interval of these "monotone" windows, there will be at
most one solution of any equality constraint. Since the boundary
of the solution set for any inequality constraint is contained in
the union of
- the set of points where an equality constraint is met
- the boundary points of the confinement window
the solutions of both equality and inequality constraints can be
found easily once the monotone windows have been found.
Step Size
=========
The monotone windows (described above) are found via a two-step
search process. Each interval of the confinement window is
searched as follows: first, the input step size is used to
determine the time separation at which the sign of the rate of
change of range rate will be sampled. Starting at
the left endpoint of an interval, samples will be taken at each
step. If a change of sign is found, a root has been bracketed; at
that point, the time at which the range rate is zero can be
found by a refinement process, for example, via binary search.
Note that the optimal choice of step size depends on the lengths
of the intervals over which the range rate function is monotone:
the step size should be shorter than the shortest of these
intervals (within the confinement window).
The optimal step size is *not* necessarily related to the lengths
of the intervals comprising the result window. For example, if
the shortest monotone interval has length 10 days, and if the
shortest result window interval has length 5 minutes, a step size
of 9.9 days is still adequate to find all of the intervals in the
result window. In situations like this, the technique of using
monotone windows yields a dramatic efficiency improvement over a
state-based search that simply tests at each step whether the
specified constraint is satisfied. The latter type of search can
miss solution intervals if the step size is longer than the
shortest solution interval.
Having some knowledge of the relative geometry of the target and
observer can be a valuable aid in picking a reasonable step size.
In general, the user can compensate for lack of such knowledge by
picking a very short step size; the cost is increased computation
time.
Note that the step size is not related to the precision with which
the endpoints of the intervals of the result window are computed.
That precision level is controlled by the convergence tolerance.
Convergence Tolerance
=====================
As described above, the root-finding process used by this routine
involves first bracketing roots and then using a search process to
locate them. "Roots" include times when extrema are attained and
times when the geometric quantity function is equal to a reference
value or adjusted extremum. All endpoints of the intervals comprising
the result window are either endpoints of intervals of the confinement
window or roots.
Once a root has been bracketed, a refinement process is used to
narrow down the time interval within which the root must lie.
This refinement process terminates when the location of the root
has been determined to within an error margin called the
"convergence tolerance." The convergence tolerance used by this
routine is set via the parameter SPICE_GF_CNVTOL.
The value of SPICE_GF_CNVTOL is set to a "tight" value so that the
tolerance doesn't limit the accuracy of solutions found by this
routine. In general the accuracy of input data will be the limiting
factor.
The user may change the convergence tolerance from the default
SPICE_GF_CNVTOL value by calling the routine gfstol_c, e.g.
gfstol_c( tolerance value in seconds )
Call gfstol_c prior to calling this routine. All subsequent
searches will use the updated tolerance value.
Searches over time windows of long duration may require use of
larger tolerance values than the default: the tolerance must be
large enough so that it, when added to or subtracted from the
confinement window's lower and upper bounds, yields distinct time
values.
Setting the tolerance tighter than SPICE_GF_CNVTOL is unlikely to be
useful, since the results are unlikely to be more accurate.
Making the tolerance looser will speed up searches somewhat,
since a few convergence steps will be omitted. However, in most
cases, the step size is likely to have a much greater effect
on processing time than would the convergence tolerance.
The Confinement Window
======================
The simplest use of the confinement window is to specify a time
interval within which a solution is sought. However, the
confinement window can, in some cases, be used to make searches
more efficient. Sometimes it's possible to do an efficient search
to reduce the size of the time period over which a relatively
slow search of interest must be performed.
Consider the following example: suppose one wishes to find the
times when the range rate between Io and the Earth attains a global
minimum over some (lengthy) time interval. There is one local
minimum every few days. The required step size for this search
must be smaller than the shortest interval on which the range rate
is monotone increasing or decreasing; this step size will be less
than half the average time between local minima. However, we know
that a global minimum can't occur when the Jupiter-Sun-Earth
angle is greater than 90 degrees. We can use a step size of a
half year to find the time period, within our original time
interval, during which this angle is less than 90 degrees; this
time period becomes the confinement window for our Earth-Io
range rate search. This way we've used a quick (due to the large
step size) search to cut out about half of the search period over
which we must perform a slower search using a small step size.
-Examples
The numerical results shown for these examples may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: standard.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
de421.bsp Planetary ephemeris
pck00009.tpc Planet orientation and
radii
naif0009.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'de421.bsp',
'pck00009.tpc',
'naif0009.tls' )
\begintext
Example:
Determine the time windows from January 1, 2007 UTC to
April 1, 2007 UTC for which the sun-moon range rate satisfies the
relation conditions with respect to a reference value of
0.3365 km/s radians (this range rate known to occur within the
search interval). Also determine the time windows corresponding
to the local maximum and minimum range rate, and the absolute
maximum and minimum range rate during the search interval.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SpiceUsr.h"
#define MAXWIN 20000
#define TIMFMT "YYYY-MON-DD HR:MN:SC.###"
#define TIMLEN 41
#define NLOOPS 7
int main( int argc, char **argv )
{
/.
Create the needed windows. Note, one window
consists of two values, so the total number
of cell values to allocate is twice
the number of intervals.
./
SPICEDOUBLE_CELL ( result, 2*MAXWIN );
SPICEDOUBLE_CELL ( cnfine, 2 );
SpiceDouble begtim;
SpiceDouble endtim;
SpiceDouble step;
SpiceDouble adjust;
SpiceDouble refval;
SpiceDouble beg;
SpiceDouble end;
SpiceChar begstr [ TIMLEN ];
SpiceChar endstr [ TIMLEN ];
SpiceChar * target = "MOON";
SpiceChar * abcorr = "NONE";
SpiceChar * obsrvr = "SUN";
SpiceInt count;
SpiceInt i;
SpiceInt j;
ConstSpiceChar * relate [NLOOPS] = { "=",
"<",
">",
"LOCMIN",
"ABSMIN",
"LOCMAX",
"ABSMAX",
};
/.
Load kernels.
./
furnsh_c( "standard.tm" );
/.
Store the time bounds of our search interval in
the cnfine confinement window.
./
str2et_c( "2007 JAN 01", &begtim );
str2et_c( "2007 APR 01", &endtim );
wninsd_c ( begtim, endtim, &cnfine );
/.
Search using a step size of 1 day (in units of seconds).
The reference value is .3365 km/s. We're not using the
adjustment feature, so we set 'adjust' to zero.
./
step = spd_c();
adjust = 0.;
refval = .3365;
for ( j = 0; j < NLOOPS; j++ )
{
printf ( "Relation condition: %s \n", relate[j] );
/.
Perform the search. The SPICE window 'result' contains
the set of times when the condition is met.
./
gfrr_c ( target,
abcorr,
obsrvr,
relate[j],
refval,
adjust,
step,
MAXWIN,
&cnfine,
&result );
count = wncard_c( &result );
/.
Display the results.
./
if (count == 0 )
{
printf ( "Result window is empty.\n\n" );
}
else
{
for ( i = 0; i < count; i++ )
{
/.
Fetch the endpoints of the Ith interval
of the result window.
./
wnfetd_c ( &result, i, &beg, &end );
timout_c ( beg, TIMFMT, TIMLEN, begstr );
timout_c ( end, TIMFMT, TIMLEN, endstr );
printf ( "Start time, drdt = %s \n", begstr );
printf ( "Stop time, drdt = %s \n", endstr );
}
}
printf("\n");
}
return( 0 );
}
The program outputs:
Relation condition: =
Start time, drdt = 2007-JAN-02 00:35:19.574
Stop time, drdt = 2007-JAN-02 00:35:19.574
Start time, drdt = 2007-JAN-19 22:04:54.899
Stop time, drdt = 2007-JAN-19 22:04:54.899
Start time, drdt = 2007-FEB-01 23:30:13.428
Stop time, drdt = 2007-FEB-01 23:30:13.428
Start time, drdt = 2007-FEB-17 11:10:46.540
Stop time, drdt = 2007-FEB-17 11:10:46.540
Start time, drdt = 2007-MAR-04 15:50:19.929
Stop time, drdt = 2007-MAR-04 15:50:19.929
Start time, drdt = 2007-MAR-18 09:59:05.959
Stop time, drdt = 2007-MAR-18 09:59:05.959
Relation condition: <
Start time, drdt = 2007-JAN-02 00:35:19.574
Stop time, drdt = 2007-JAN-19 22:04:54.899
Start time, drdt = 2007-FEB-01 23:30:13.428
Stop time, drdt = 2007-FEB-17 11:10:46.540
Start time, drdt = 2007-MAR-04 15:50:19.929
Stop time, drdt = 2007-MAR-18 09:59:05.959
Relation condition: >
Start time, drdt = 2007-JAN-01 00:00:00.000
Stop time, drdt = 2007-JAN-02 00:35:19.574
Start time, drdt = 2007-JAN-19 22:04:54.899
Stop time, drdt = 2007-FEB-01 23:30:13.428
Start time, drdt = 2007-FEB-17 11:10:46.540
Stop time, drdt = 2007-MAR-04 15:50:19.929
Start time, drdt = 2007-MAR-18 09:59:05.959
Stop time, drdt = 2007-APR-01 00:00:00.000
Relation condition: LOCMIN
Start time, drdt = 2007-JAN-11 07:03:58.988
Stop time, drdt = 2007-JAN-11 07:03:58.988
Start time, drdt = 2007-FEB-10 06:26:15.439
Stop time, drdt = 2007-FEB-10 06:26:15.439
Start time, drdt = 2007-MAR-12 03:28:36.404
Stop time, drdt = 2007-MAR-12 03:28:36.404
Relation condition: ABSMIN
Start time, drdt = 2007-JAN-11 07:03:58.988
Stop time, drdt = 2007-JAN-11 07:03:58.988
Relation condition: LOCMAX
Start time, drdt = 2007-JAN-26 02:27:33.766
Stop time, drdt = 2007-JAN-26 02:27:33.766
Start time, drdt = 2007-FEB-24 09:35:07.816
Stop time, drdt = 2007-FEB-24 09:35:07.816
Start time, drdt = 2007-MAR-25 17:26:56.150
Stop time, drdt = 2007-MAR-25 17:26:56.150
Relation condition: ABSMAX
Start time, drdt = 2007-MAR-25 17:26:56.150
Stop time, drdt = 2007-MAR-25 17:26:56.150
-Restrictions
1) The kernel files to be used by this routine must be loaded
(normally using the CSPICE routine furnsh_c) before this
routine is called.
2) This routine has the side effect of re-initializing the
range rate quantity utility package. Callers may themselves
need to re-initialize the range rate quantity utility
package after calling this routine.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
E.D. Wright (JPL)
-Version
-CSPICE Version 1.0.1, 28-FEB-2013 (NJB) (EDW)
Header was updated to discuss use of gfstol_c.
Edit to comments to correct search description.
Edits to Example section, proper description of "standard.tm"
meta kernel.
-CSPICE Version 1.0.0, 26-AUG-2009 (EDW) (NJB)
-Index_Entries
GF range rate search
-&
*/
{ /* Begin gfrr_c */
/*
Local variables
*/
doublereal * work;
static SpiceInt nw = SPICE_GF_NWRR;
SpiceInt nBytes;
/*
Participate in error tracing.
*/
chkin_c ( "gfrr_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2 ( CHK_STANDARD, "gfrr_c", SPICE_DP, cnfine, result );
/*
Initialize the input cells if necessary.
*/
CELLINIT2 ( cnfine, result );
/*
Check the input strings to make sure each pointer is non-null
and each string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "gfrr_c", target );
CHKFSTR ( CHK_STANDARD, "gfrr_c", abcorr );
CHKFSTR ( CHK_STANDARD, "gfrr_c", obsrvr );
CHKFSTR ( CHK_STANDARD, "gfrr_c", relate );
/*
Check the workspace size; some mallocs have a violent
dislike for negative allocation amounts. To be safe,
rule out a count of zero intervals as well.
*/
if ( nintvls < 1 )
{
setmsg_c ( "The specified workspace interval count # was "
"less than the minimum allowed value of one (1)." );
errint_c ( "#", nintvls );
sigerr_c ( "SPICE(VALUEOUTOFRANGE)" );
chkout_c ( "gfrr_c" );
return;
}
/*
Allocate the workspace. 'nintvls' indicates the maximum number of
intervals returned in 'result'. An interval consists of
two values.
*/
nintvls = 2 * nintvls;
nBytes = ( nintvls + SPICE_CELL_CTRLSZ ) * nw * sizeof(SpiceDouble);
work = (doublereal *) alloc_SpiceMemory( nBytes );
if ( !work )
{
setmsg_c ( "Workspace allocation of # bytes failed due to "
"malloc failure" );
errint_c ( "#", nBytes );
sigerr_c ( "SPICE(MALLOCFAILED)" );
chkout_c ( "gfrr_c" );
return;
}
/*
Let the f2'd routine do the work.
*/
gfrr_( ( char * ) target,
( char * ) abcorr,
( char * ) obsrvr,
( char * ) relate,
( doublereal * ) &refval,
( doublereal * ) &adjust,
( doublereal * ) &step,
( doublereal * ) (cnfine->base),
( integer * ) &nintvls,
( integer * ) &nw,
( doublereal * ) work,
( doublereal * ) (result->base),
( ftnlen ) strlen(target),
( ftnlen ) strlen(abcorr),
( ftnlen ) strlen(obsrvr),
( ftnlen ) strlen(relate) );
/*
De-allocate the workspace.
*/
free_SpiceMemory( work );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, result ) ;
}
ALLOC_CHECK;
chkout_c ( "gfrr_c" );
} /* End gfrr_c */
int zzgfdsps_ ( integer * nlead,
char * string,
char * fmt,
integer * ntrail,
ftnlen stringLen,
ftnlen fmtLen )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
nlead I Number of leading blank lines to write.
string I The string to display.
fmt I Format in which the string is to be written.
ntrail I Number of trailing blank lines to write.
stringLen I Length of input argument `string'.
fmtLen I Length of input argument `fmt'.
-Detailed_Input
nlead is the number of blank lines to write before
writing the output text string.
string is a message to be displayed on the standard
output stream. This is a Fortran-style string
without a terminating null character.
fmt is a Fortran format specification used to write
the output string. This is a Fortran-style string
without a terminating null character.
FMT may be left to default ("A"), or may be used
to control the length of the string ("A10").
**NOTE**: this argument is provided only for
compatibility with the Fortran version of this
routine; the argument is currently ignored.
ntrail is the number of blank lines to write after
writing the output text string.
stringLen is the length of the input string `string'.
fmtLen is the length of the input string `fmt'.
-Detailed_Output
None. This program has no output arguments but writes to the
standard output stream.
-Parameters
None.
-Exceptions
1) If an error occurs when this routine attempts to
allocate memory dynamically, the error will be
diagnosed by routines in the call tree of this routine.
2) If the either of the input arguments `nlead' or `ntrail'
is non-positive, then no leading or trailing blank
lines will be written, respectively. This case is not
considered an error.
-Files
None.
-Particulars
This is an overlay routine for the f2c'd routine zzgfdsps_;
as such, this routine has an f2c-style calling sequence.
CSPICE GF routines should call this routine rather than
zzgfdsps_.
Since ANSI C supports the cursor control capabilities required
for GF progress reporting, it's not necessary to rely on ANSI
control sequences to effect cursor control.
This routine supports the default GF progress report display.
Output is written to the standard output stream; normally this
results in output on a terminal window.
After the output line is written, this routine moves the cursor
up and to the first column, so a subsequent call will overwrite
output from the current call.
-Examples
See calls made to this routine by the entry points of
zzgfrpwrk.
-Restrictions
The input Fortran format argument is ignored.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.0.0, 27-FEB-2009 (NJB)
-Index_Entries
GF output progress report string
-&
*/
{ /* Begin zzgfdsps_ */
/*
Local variables
*/
SpiceChar * CFmtPtr;
SpiceChar * CStringPtr;
SpiceInt i;
SpiceInt nl;
SpiceInt nt;
SpiceInt outlen;
/*
Participate in error tracing.
*/
chkin_c ( "zzgfdsps_" );
/*
The input strings are Fortran-style; they're not
null-terminated. Convert these to C-style strings
so we can work with them. We'll need to use dynamic
memory to hold the C-style strings.
*/
F2C_CreateStr_Sig ( stringLen, string, &CStringPtr );
if ( failed_c() )
{
/*
The CSPICE string utilities do their own clean-up of
allocated memory, so we won't attempt to free the
C string.
*/
chkout_c ( "zzgfdsps_" );
return (-1);
}
F2C_CreateStr_Sig ( fmtLen, fmt, &CFmtPtr );
if ( failed_c() )
{
/*
Failure at this point requires that we free the previous,
successfully allocated string.
*/
free ( CStringPtr );
chkout_c ( "zzgfdsps_" );
return(-1);
}
/*
Display any blank lines indicated by `nlead'.
*/
nl = *nlead;
nt = *ntrail;
for ( i = 0; i < nl; i++ )
{
putc ( '\n', stdout );
}
/*
Save the length of the output string.
*/
outlen = strlen( CStringPtr );
/*
Write the string to standard output without a trailing newline
character.
*/
printf ( "%s", CStringPtr );
/*
Force a write of any buffered, unwritten output data.
Without this call, progress report updates may not be displayed in a
timely fashion. There can be a long pause, followed by an
announcement that the task is 100% done. This behavior rather
defeats the purpose of the report.
*/
fflush ( stdout );
/*
Back up the cursor to the start of the line.
*/
for ( i = 0; i < outlen; i++ )
{
putc ( '\b', stdout );
}
/*
Display any blank lines indicated by `ntrail'.
*/
for ( i = 0; i < nt; i++ )
{
putc ( '\n', stdout );
}
/*
Free the dynamically allocated strings.
*/
free ( CStringPtr );
free ( CFmtPtr );
chkout_c ( "zzgfdsps_" );
return ( 0 );
} /* End zzgfdsps_ */
void wninsd_c ( SpiceDouble left,
SpiceDouble right,
SpiceCell * window )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
left,
right I Left, right endpoints of new interval.
window I,O Input, output window.
-Detailed_Input
left,
right are the left and right endpoints of the interval
to be inserted.
window on input, is a CSPICE window containing zero or more
intervals.
window must be declared as a double precision
SpiceCell.
-Detailed_Output
window on output, is the original window following the
insertion of the interval from left to right.
-Parameters
None.
-Exceptions
1) If the input window does not have double precision type,
the error SPICE(TYPEMISMATCH) is signaled.
2) If left is greater than right, the error SPICE(BADENDPOINTS) is
signaled.
3) If the insertion of the interval causes an excess of elements,
the error SPICE(WINDOWEXCESS) is signaled.
-Files
None.
-Particulars
This routine inserts the interval from left to right into the
input window. If the new interval overlaps any of the intervals
in the window, the intervals are merged. Thus, the cardinality
of the input window can actually decrease as the result of an
insertion. However, because inserting an interval that is
disjoint from the other intervals in the window can increase the
cardinality of the window, the routine signals an error.
No other CSPICE unary window routine can increase the number of
intervals in the input window.
-Examples
Let window contain the intervals
[ 1, 3 ] [ 7, 11 ] [ 23, 27 ]
Then the following series of calls
wninsd_c ( 5.0, 5.0, &window ) (1)
wninsd_c ( 4.0, 8.0, &window ) (2)
wninsd_c ( 0.0, 30.0, &window ) (3)
produces the following series of windows
[ 1, 3 ] [ 5, 5 ] [ 7, 11 ] [ 23, 27 ] (1)
[ 1, 3 ] [ 4, 11 ] [ 23, 27 ] (2)
[ 0, 30 ] (3)
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
K.R. Gehringer (JPL)
H.A. Neilan (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
-Version
-CSPICE Version 1.0.0, 29-JUL-2002 (NJB) (KRG) (HAN) (WLT) (IMU)
-Index_Entries
insert an interval into a d.p. window
-&
*/
{ /* Begin wninsd_c */
/*
Standard SPICE error handling.
*/
if ( return_c() )
{
return;
}
chkin_c ( "wninsd_c" );
/*
Make sure cell data type is d.p.
*/
CELLTYPECHK ( CHK_STANDARD, "wninsd_c", SPICE_DP, window );
/*
Initialize the cell if necessary.
*/
CELLINIT ( window );
/*
Let the f2c'd routine do the work.
*/
wninsd_ ( (doublereal * ) &left,
(doublereal * ) &right,
(doublereal * ) (window->base) );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, window );
}
chkout_c ( "wninsd_c" );
} /* End wninsd_c */
void pcpool_c ( ConstSpiceChar * name,
SpiceInt n,
SpiceInt lenvals,
const void * cvals )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
name I The kernel pool name to associate with cvals.
n I The number of values to insert.
lenvals I The lengths of the strings in the array cvals.
cvals I An array of strings to insert into the kernel pool.
-Detailed_Input
name is the name of the kernel pool variable to associate
with the values supplied in the array cvals. 'name' is
restricted to a length of 32 characters or less.
n is the number of values to insert into the kernel pool.
lenvals is the length of the strings in the array cvals,
including the null terminators.
cvals is an array of strings to insert into the kernel
pool. cvals should be declared as follows:
char cvals[n][lenvals];
-Detailed_Output
None.
-Parameters
None.
-Exceptions
1) If name is already present in the kernel pool and there
is sufficient room to hold all values supplied in values,
the old values associated with name will be overwritten.
2) If there is not sufficient room to insert a new variable
into the kernel pool and name is not already present in
the kernel pool, the error SPICE(KERNELPOOLFULL) is
signaled by a routine in the call tree to this routine.
3) If there is not sufficient room to insert the values associated
with name, the error SPICE(NOMOREROOM) will be signaled.
4) If either input string pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
5) If the input string name has length zero, the error
SPICE(EMPTYSTRING) will be signaled.
6) If the input cvals string length is less than 2, the error
SPICE(STRINGTOOSHORT) will be signaled.
7) The error 'SPICE(BADVARNAME)' signals if the kernel pool
variable name length exceeds 32.
-Files
None.
-Particulars
This entry point provides a programmatic interface for inserting
character data into the SPICE kernel pool without reading an
external file.
-Examples
The following example program shows how a topocentric frame for a
point on the surface of the earth may be defined at run time using
pcpool_c, pdpool_c, and pipool_c. In this example, the surface
point is associated with the body code 300000. To facilitate
testing, the location of the surface point coincides with that of
the DSN station DSS-12; the reference frame MYTOPO defined here
coincides with the reference frame DSS-12_TOPO.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
The first angle is the negative of the longitude of the
surface point; the second angle is the negative of the
point's colatitude.
./
SpiceDouble angles [3] = { -243.1945102442646,
-54.7000629043147,
180.0 };
SpiceDouble et = 0.0;
SpiceDouble rmat [3][3];
SpiceInt axes [3] = { 3, 2, 3 };
SpiceInt center = 300000;
SpiceInt frclass = 4;
SpiceInt frclsid = 1500000;
SpiceInt frcode = 1500000;
/.
Define the MYTOPO reference frame.
Note that the third argument in the pcpool_c calls is
the length of the final string argument, including the
terminating null character.
./
pipool_c ( "FRAME_MYTOPO", 1, &frcode );
pcpool_c ( "FRAME_1500000_NAME", 1, 7, "MYTOPO" );
pipool_c ( "FRAME_1500000_CLASS", 1, &frclass );
pipool_c ( "FRAME_1500000_CLASS_ID", 1, &frclsid );
pipool_c ( "FRAME_1500000_CENTER", 1, ¢er );
pcpool_c ( "OBJECT_300000_FRAME", 1, 7, "MYTOPO" );
pcpool_c ( "TKFRAME_MYTOPO_RELATIVE", 1, 7, "ITRF93" );
pcpool_c ( "TKFRAME_MYTOPO_SPEC", 1, 7, "ANGLES" );
pcpool_c ( "TKFRAME_MYTOPO_UNITS", 1, 8, "DEGREES" );
pipool_c ( "TKFRAME_MYTOPO_AXES", 3, axes );
pdpool_c ( "TKFRAME_MYTOPO_ANGLES", 3, angles );
/.
Load a high precision binary earth PCK. Also load a
topocentric frame kernel for DSN stations. The file names
shown here are simply examples; users should replace these
with the names of appropriate kernels.
./
furnsh_c ( "earth_000101_060207_051116.bpc" );
furnsh_c ( "earth_topo_050714.tf" );
/.
Look up transformation from DSS-12_TOPO frame to MYTOPO frame.
This transformation should differ by round-off error from
the identity matrix.
./
pxform_c ( "DSS-12_TOPO", "MYTOPO", et, rmat );
printf ( "\n"
"DSS-12_TOPO to MYTOPO transformation at "
"et %23.16e = \n"
"\n"
" %25.16f %25.16f %25.16f\n"
" %25.16f %25.16f %25.16f\n"
" %25.16f %25.16f %25.16f\n",
et,
rmat[0][0], rmat[0][1], rmat[0][2],
rmat[1][0], rmat[1][1], rmat[1][2],
rmat[2][0], rmat[2][1], rmat[2][2] );
return ( 0 );
}
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
W.L. Taber (JPL)
-Version
-CSPICE Version 1.3.3, 17-JAN-2014 (NJB)
Updated Index_Entries section.
-CSPICE Version 1.3.2, 10-FEB-2010 (EDW)
Added mention of the restriction on kernel pool variable
names to 32 characters or less.
Reordered header sections to conform to SPICE convention.
-CSPICE Version 1.3.1, 17-NOV-2005 (NJB)
Replaced code fragment in Examples section of header with
smaller, complete program.
-CSPICE Version 1.3.0, 12-JUL-2002 (NJB)
Call to C2F_CreateStrArr_Sig replaced with call to C2F_MapStrArr.
-CSPICE Version 1.2.0, 28-AUG-2001 (NJB)
Const-qualified input array cvals.
-CSPICE Version 1.1.0, 14-FEB-2000 (NJB)
Calls to C2F_CreateStrArr replaced with calls to error-signaling
version of this routine: C2F_CreateStrArr_Sig.
-CSPICE Version 1.0.0, 18-JUN-1999 (NJB) (WLT)
-Index_Entries
Set the value of a character_variable in the kernel_pool
-&
*/
{ /* Begin pcpool_c */
/*
Local variables
*/
SpiceChar * fCvalsArr;
SpiceInt fCvalsLen;
/*
Participate in error tracing.
*/
chkin_c ( "pcpool_c" );
/*
Check the input kernel variable name to make sure the pointer is
non-null and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "pcpool_c", name );
/*
Make sure the input string pointer for the cvals array is non-null
and that the length lenvals is sufficient.
*/
CHKOSTR ( CHK_STANDARD, "pcpool_c", cvals, lenvals );
/*
Create a Fortran-style string array.
*/
C2F_MapStrArr ( "pcpool_c",
n, lenvals, cvals, &fCvalsLen, &fCvalsArr );
if ( failed_c() )
{
chkout_c ( "pcpool_c" );
return;
}
/*
Call the f2c'd routine.
*/
pcpool_ ( ( char * ) name,
( integer * ) &n,
( char * ) fCvalsArr,
( ftnlen ) strlen(name),
( ftnlen ) fCvalsLen );
/*
Free the dynamically allocated array.
*/
free ( fCvalsArr );
chkout_c ( "pcpool_c" );
} /* End pcpool_c */
/**
* This method looks for any naif errors that might have occurred. It
* then compares the error to a list of known naif errors and converts
* the error into an iException.
*
* @param resetNaif True if the NAIF error status should be reset (naif calls valid)
*/
void NaifStatus::CheckErrors(bool resetNaif) {
if(!initialized) {
SpiceChar returnAct[32] = "RETURN";
SpiceChar printAct[32] = "NONE";
erract_c ( "SET", sizeof(returnAct), returnAct); // Reset action to return
errprt_c ( "SET", sizeof(printAct), printAct); // ... and print nothing
initialized = true;
}
// Do nothing if NAIF didn't fail
//getmsg_c("", 0, NULL);
if(!failed_c()) return;
// This method has been documented with the information provided
// from the NAIF documentation at:
// naif/cspice61/packages/cspice/doc/html/req/error.html
// This message is a character string containing a very terse, usually
// abbreviated, description of the problem. The message is a character
// string of length not more than 25 characters. It always has the form:
// SPICE(...)
// Short error messages used in CSPICE are CONSTANT, since they are
// intended to be used in code. That is, they don't contain any data which
// varies with the specific instance of the error they indicate.
// Because of the brief format of the short error messages, it is practical
// to use them in a test to determine which type of error has occurred.
const int SHORT_DESC_LEN = 26;
SpiceChar naifShort[SHORT_DESC_LEN];
getmsg_c("SHORT", SHORT_DESC_LEN, naifShort);
// This message may be up to 1840 characters long. The CSPICE error handling
// mechanism makes no use of its contents. Its purpose is to provide human-readable
// information about errors. Long error messages generated by CSPICE routines often
// contain data relevant to the specific error they describe.
const int LONG_DESC_LEN = 1841;
SpiceChar naifLong[LONG_DESC_LEN];
getmsg_c("LONG", LONG_DESC_LEN, naifLong);
// Search for known naif errors...
iString errMsg;
Pvl error;
PvlGroup errorDescription("ErrorDescription");
errorDescription.AddKeyword(PvlKeyword("ShortMessage", naifShort));
errorDescription.AddKeyword(PvlKeyword("LongMessage", naifLong));
error.AddGroup(errorDescription);
PvlTranslationManager trans(error, "$base/translations/NaifErrors.trn");
try {
errMsg = trans.Translate("ShortMessage");
}
catch(iException &e) {
e.Clear();
errMsg = "An unknown NAIF error has been encountered.";
}
try {
errMsg += " " + trans.Translate("LongMessage");
}
catch(iException &e) {
e.Clear();
}
// Now process the error
if(resetNaif) {
reset_c();
}
errMsg += " The short explanation ";
errMsg += "provided by NAIF is [" + iString(naifShort) + "]. ";
errMsg += "The Naif error is [" + iString(naifLong) + "]";
throw iException::Message(iException::Spice, errMsg, _FILEINFO_);
}
void wnintd_c ( SpiceCell * a,
SpiceCell * b,
SpiceCell * c )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
a,
b I Input windows.
c O Intersection of a and b.
-Detailed_Input
a,
b are CSPICE windows, each of which contains zero or more
intervals.
a and b must be declared as double precision
SpiceCells.
-Detailed_Output
c is the output CSPICE window, containing the intersection
of a and b---every point contained in both a and b.
c must be declared as a double precision SpiceCell.
c must be distinct from both a and b.
-Parameters
None.
-Exceptions
1) If any of the function arguments are SpiceCells of type
other than double precision, the error SPICE(TYPEMISMATCH)
is signaled.
2) If the intersection of the two windows results in an excess of
elements, the error SPICE(WINDOWEXCESS) is signaled.
-Files
None.
-Particulars
The intersection of two windows contains every point contained
both in the first window and in the second window.
-Examples
Let a contain the intervals
[ 1, 3 ] [ 7, 11 ] [ 23, 27 ]
and b contain the intervals
[ 2, 4 ] [ 8, 10 ] [ 16, 18 ]
Then the intersection of a and b contains the intervals
[ 2, 3 ] [ 8, 10 ]
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
H.A. Neilan (JPL)
B.V. Semenov (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
-Version
-CSPICE Version 1.0.1, 11-FEB-2013 (BVS)
Corrected typo in Brief I/O section.
-CSPICE Version 1.0.0, 29-JUL-2002 (NJB) (HAN) (WLT) (IMU)
-Index_Entries
intersect two d.p. windows
-&
*/
{ /* Begin wnintd_c */
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "wnintd_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK3 ( CHK_STANDARD, "wnintd_c", SPICE_DP, a, b, c );
/*
Initialize the cells if necessary.
*/
CELLINIT3 ( a, b, c );
/*
Let the f2c'd routine do the work.
*/
wnintd_ ( (doublereal * ) (a->base),
(doublereal * ) (b->base),
(doublereal * ) (c->base) );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, c );
}
chkout_c ( "wnintd_c" );
} /* End wnintd_c */
void uddc_c ( void ( * udfunc ) ( SpiceDouble x,
SpiceDouble * value ),
SpiceDouble x,
SpiceDouble dx,
SpiceBoolean * isdecr )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
udfunc I The routine that computes the scalar value
of interest.
x I Independent variable of 'udfunc'.
dx I Interval from 'x' for derivative calculation.
isdecr O Boolean indicating if the derivative is negative.
-Detailed_Input
udfunc the routine that returns the value of the scalar quantity
function of interest at X. The calling sequence for UDFUNC is:
udfunc ( x, &value );
where:
x the double precision value of the
independent variable of the function
at which to determine the scalar value.
value the double precision value returned by
'udfunc' at 'x'.
Functionally:
value = udfunc ( x )
x a scalar double precision value at which to determine
the derivative of 'udfunc'.
For many SPICE uses, 'x' will represent ephemeris time,
expressed as seconds past J2000 TDB.
dx a scalar double precision value representing half the
interval in units of 'x' separating the evaluation
values of 'udfunc'; the evaluations occur at (x + dx)
and (x - dx).
'dx' may be negative but must be non-zero.
-Detailed_Output
isdecr a scalar boolean indicating if the first derivative
of 'udfunc' with respect to time at 'et' is less than
zero.
Functionally:
d udfunc(x) |
-- | < 0
dx |
x
-Parameters
None.
-Exceptions
1) A routine in the call tree of this routine signals
SPICE(DIVIDEBYZERO) if DX has a value of zero.
-Files
If the evaluation of 'udfunc' requires SPICE kernel data, the
appropriate kernels must be loaded before calling this routine.
- SPK data: the calling application must load ephemeris data
for the targets, observer, and any intermediate objects in
a chain connecting the targets and observer for the time
used in the evaluation. If aberration corrections are used,
the states of target and observer relative to the solar system
barycenter must be calculable from the available ephemeris
data.
- If non-inertial reference frames are used, then PCK
files, frame kernels, C-kernels, and SCLK kernels may be
needed.
Such kernel data are normally loaded once per program run, NOT
every time this routine is called.
-Particulars
None.
-Examples
See gfuds_c.
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
E.D. Wright (JPL)
-Version
-CSPICE Version 1.0.0, 31-MAR-2010 (EDW)
-Index_Entries
first derivative less-than zero
-&
*/
{
SpiceDouble deriv;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "uddc_c" );
*isdecr = SPICEFALSE;
uddf_c ( udfunc, x, dx, &deriv );
if ( failed_c() )
{
chkout_c ( "uddc_c" );
return;
}
*isdecr = deriv < 0.;
chkout_c ( "uddc_c" );
return;
}
void gfpa_c ( ConstSpiceChar * target,
ConstSpiceChar * illmn,
ConstSpiceChar * abcorr,
ConstSpiceChar * obsrvr,
ConstSpiceChar * relate,
SpiceDouble refval,
SpiceDouble adjust,
SpiceDouble step,
SpiceInt nintvls,
SpiceCell * cnfine,
SpiceCell * result )
/*
-Brief_I/O
Variable I/O Description
--------------- --- ------------------------------------------------
SPICE_GF_CNVTOL P Convergence tolerance
target I Name of the target body.
illmn I Name of the illuminating body.
abcorr I Aberration correction flag.
obsrvr I Name of the observing body.
relate I Relational operator.
refval I Reference value.
adjust I Adjustment value for absolute extrema searches.
step I Step size used for locating extrema and roots.
nintvls I Workspace window interval count.
cnfine I-O SPICE window to which the search is confined.
result O SPICE window containing results.
-Detailed_Input
target is the name of a target body. Optionally, you may supply
a string containing the integer ID code for the object.
For example both "MOON" and "301" are legitimate strings
that indicate the Moon is the target body.
Case and leading or trailing blanks are not significant
in the string `target'.
illmn the string name of the illuminating body. This will
normally be "SUN" but the algorithm can use any
ephemeris object
Case and leading or trailing blanks are not significant
in the string `illmn'.
abcorr indicates the aberration corrections to be applied to
the observer-target position vector to account for
one-way light time and stellar aberration.
Any aberration correction accepted by the SPICE
routine spkezr_c is accepted here. See the header
of spkezr_c for a detailed description of the
aberration correction options. For convenience,
the allowed aberation options are listed below:
"NONE" Apply no correction.
"LT" "Reception" case: correct for
one-way light time using a Newtonian
formulation.
"LT+S" "Reception" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
"CN" "Reception" case: converged
Newtonian light time correction.
"CN+S" "Reception" case: converged
Newtonian light time and stellar
aberration corrections.
Note that this routine accepts only reception mode
aberration corrections.
Case and leading or trailing blanks are not significant
in the string `abcorr'.
obsrvr is the name of the observing body. Optionally, you may
supply a string containing the integer ID code for the
object. For example both "MOON" and "301" are legitimate
strings that indicate the Moon is the observer.
Case and leading or trailing blanks are not significant
in the string `obsrvr'.
relate is a relational operator used to define a constraint on
the phase angle. The result window found by
this routine indicates the time intervals where the
constraint is satisfied. Supported values of `relate'
and corresponding meanings are shown below:
">" The phase angle value is greater than the
reference value REFVAL.
"=" The phase angle value is equal to the
reference value REFVAL.
"<" The phase angle value is less than the
reference value REFVAL.
"ABSMAX" The phase angle value is at an absolute
maximum.
"ABSMIN" The phase angle value is at an absolute
minimum.
"LOCMAX" The phase angle value is at a local
maximum.
"LOCMIN" The phase angle value is at a local
minimum.
`relate' may be used to specify an "adjusted" absolute
extremum constraint: this requires the phase angle
to be within a specified offset relative to an
absolute extremum. The argument `adjust' (described
below) is used to specify this offset.
Local extrema are considered to exist only in the
interiors of the intervals comprising the confinement
window: a local extremum cannot exist at a boundary
point of the confinement window.
Case and leading or trailing blanks are not significant
in the string `relate'.
`refval' is the reference value used together with the argument
`relate' to define an equality or inequality to be
satisfied by the phase angle. See the discussion of
`relate' above for further information.
The units of `refval' are radians.
adjust is a parameter used to modify searches for absolute
extrema: when `relate' is set to "ABSMAX" or "ABSMIN"
and `adjust' is set to a positive value, gfpa_c will
find times when the phase angle is within
`adjust' radians of the specified extreme value.
If `adjust' is non-zero and a search for an absolute
minimum `min' is performed, the result window contains
time intervals when the phase angle has values between
`min' and min+adjust.
If the search is for an absolute maximum `max', the
corresponding range is from max-adjust to `max'.
`adjust' is not used for searches for local extrema,
equality or inequality conditions.
step is the step size to be used in the search. `step' must
be shorter than any maximal time interval on which the
specified phase angle function is monotone increasing or
decreasing. That is, if the confinement window is
partitioned into alternating intervals on which the
phase angle function is either monotone increasing or
decreasing, `step' must be shorter than any of these
intervals.
However, `step' must not be *too* short, or the search
will take an unreasonable amount of time.
The choice of `step' affects the completeness but not
the precision of solutions found by this routine; the
precision is controlled by the convergence tolerance.
See the discussion of the parameter SPICE_GF_CNVTOL for
details.
STEP has units of TDB seconds.
nintvls is a parameter specifying the number of intervals that
can be accommodated by each of the dynamically allocated
workspace windows used internally by this routine.
In many cases, it's not necessary to compute an accurate
estimate of how many intervals are needed; rather, the
user can pick a size considerably larger than what's
really required.
However, since excessively large arrays can prevent
applications from compiling, linking, or running
properly, sometimes `nintvls' must be set according to
the actual workspace requirement. A rule of thumb for
the number of intervals needed is
nintvls = 2*n + ( m / step )
where
n is the number of intervals in the confinement
window
m is the measure of the confinement window, in
units of seconds
`step' is the search step size in seconds
cnfine is a SPICE window that confines the time period over
which the specified search is conducted. `cnfine' may
consist of a single interval or a collection of
intervals.
The endpoints of the time intervals comprising `cnfine'
are interpreted as seconds past J2000 TDB.
See the Examples section below for a code example that
shows how to create a confinement window.
-Detailed_Output
cnfine is the input confinement window, updated if necessary so
the control area of its data array indicates the
window's size and cardinality. The window data are
unchanged.
result is the window of intervals, contained within the
confinement window `cnfine', on which the specified
phase angle constraint is satisfied.
The endpoints of the time intervals comprising `result'
are interpreted as seconds past J2000 TDB.
If `result' is non-empty on input, its contents will be
discarded before gfpa_c conducts its search.
-Parameters
SPICE_GF_CNVTOL
is the convergence tolerance used for finding endpoints
of the intervals comprising the result window.
SPICE_GF_CNVTOL is used to determine when binary
searches for roots should terminate: when a root is
bracketed within an interval of length SPICE_GF_CNVTOL,
the root is considered to have been found.
The accuracy, as opposed to precision, of roots found by
this routine depends on the accuracy of the input data.
In most cases, the accuracy of solutions will be
inferior to their precision.
SPICE_GF_CNVTOL is declared in the header file
SpiceGF.h.
-Exceptions
1) In order for this routine to produce correct results,
the step size must be appropriate for the problem at hand.
Step sizes that are too large may cause this routine to miss
roots; step sizes that are too small may cause this routine
to run unacceptably slowly and in some cases, find spurious
roots.
This routine does not diagnose invalid step sizes, except
that if the step size is non-positive, an error is signaled
by a routine in the call tree of this routine.
2) Due to numerical errors, in particular,
- Truncation error in time values
- Finite tolerance value
- Errors in computed geometric quantities
it is *normal* for the condition of interest to not always be
satisfied near the endpoints of the intervals comprising the
result window.
The result window may need to be contracted slightly by the
caller to achieve desired results. The SPICE window routine
wncond_c can be used to contract the result window.
3) If an error (typically cell overflow) occurs while performing
window arithmetic, the error will be diagnosed by a routine
in the call tree of this routine.
4) If the relational operator `relate' is not recognized, an
error is signaled by a routine in the call tree of this
routine.
5) If the aberration correction specifier contains an
unrecognized value, an error is signaled by a routine in the
call tree of this routine.
6) If `adjust' is negative, an error is signaled by a routine in
the call tree of this routine.
7) If either of the input body names do not map to NAIF ID
codes, an error is signaled by a routine in the call tree of
this routine.
8) If required ephemerides or other kernel data are not
available, an error is signaled by a routine in the call tree
of this routine.
9) If the workspace interval count is less than 1, the error
SPICE(VALUEOUTOFRANGE) will be signaled.
10) If the required amount of workspace memory cannot be
allocated, the error SPICE(MALLOCFAILURE) will be
signaled.
11) If the output SPICE window `result' has insufficient capacity to
contain the number of intervals on which the specified geometric
condition is met, the error will be diagnosed by a routine in
the call tree of this routine. If the result window has size
less than 2, the error SPICE(INVALIDDIMENSION) will be signaled
by this routine.
12) If any input string argument pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
13) If any input string argument is empty, the error
SPICE(EMPTYSTRING) will be signaled.
14) If either input cell has type other than SpiceDouble,
the error SPICE(TYPEMISMATCH) is signaled.
15) An error signals from a routine in the call tree of
this routine for any transmit mode aberration correction.
-Files
Appropriate SPK and PCK kernels must be loaded by the calling
program before this routine is called.
The following data are required:
- SPK data: the calling application must load ephemeris data
for the targets, observer, and any intermediate objects in
a chain connecting the targets and observer that cover the
time period specified by the window CNFINE. If aberration
corrections are used, the states of target and observer
relative to the solar system barycenter must be calculable
from the available ephemeris data. Typically ephemeris data
are made available by loading one or more SPK files using
furnsh_c.
Kernel data are normally loaded once per program run, NOT every
time this routine is called.
-Particulars
ILLMN OBS
ILLMN as seen * /
from TARG at | /
ET - LT. | /
>|..../< phase angle
| /
. | /
. | /
. * TARG as seen from OBS
SEP . TARG at ET
. /
/
*
This routine determines if the caller-specified constraint
condition on the geometric event (phase angle) is satisfied for
any time intervals within the confinement window `cnfine'. If one
or more such time intervals exist, those intervals are added
to the `result' window.
This routine provides a simpler, but less flexible interface
than does the routine gfevnt_c for conducting searches for
illuminator-target-observer phase angle value events.
Applications that require support for progress reporting,
interrupt handling, non-default step or refinement functions
should call gfevnt_c rather than this routine.
Below we discuss in greater detail aspects of this routine's
solution process that are relevant to correct and efficient
use of this routine in user applications.
The Search Process
==================
Regardless of the type of constraint selected by the caller, this
routine starts the search for solutions by determining the time
periods, within the confinement window, over which the
phase angle function is monotone increasing and monotone
decreasing. Each of these time periods is represented by a SPICE
window. Having found these windows, all of the phase angle
function's local extrema within the confinement window are known.
Absolute extrema then can be found very easily.
Within any interval of these "monotone" windows, there will be at
most one solution of any equality constraint. Since the boundary
of the solution set for any inequality constraint is contained in
the union of
- the set of points where an equality constraint is met
- the boundary points of the confinement window
the solutions of both equality and inequality constraints can be
found easily once the monotone windows have been found.
Step Size
=========
The monotone windows (described above) are found using a two-step
search process. Each interval of the confinement window is
searched as follows: first, the input step size is used to
determine the time separation at which the sign of the rate of
change of phase angle will be sampled. Starting at
the left endpoint of an interval, samples will be taken at each
step. If a change of sign is found, a root has been bracketed; at
that point, the time at which the time derivative of the
phase angle is zero can be found by a refinement process, for
example, using a binary search.
Note that the optimal choice of step size depends on the lengths
of the intervals over which the phase angle function is monotone:
the step size should be shorter than the shortest of these
intervals (within the confinement window).
The optimal step size is *not* necessarily related to the lengths
of the intervals comprising the result window. For example, if
the shortest monotone interval has length 10 days, and if the
shortest result window interval has length 5 minutes, a step size
of 9.9 days is still adequate to find all of the intervals in the
result window. In situations like this, the technique of using
monotone windows yields a dramatic efficiency improvement over a
state-based search that simply tests at each step whether the
specified constraint is satisfied. The latter type of search can
miss solution intervals if the step size is longer than the
shortest solution interval.
Having some knowledge of the relative geometry of the target,
illumination source, and observer can be a valuable aid in
picking a reasonable step size. In general, the user can
compensate for lack of such knowledge by picking a very short
step size; the cost is increased computation time.
Note that the step size is not related to the precision with which
the endpoints of the intervals of the result window are computed.
That precision level is controlled by the convergence tolerance.
Convergence Tolerance
=====================
As described above, the root-finding process used by this routine
involves first bracketing roots and then using a search process to
locate them. "Roots" include times when extrema are attained and
times when the geometric quantity function is equal to a reference
value or adjusted extremum. All endpoints of the intervals comprising
the result window are either endpoints of intervals of the confinement
window or roots.
Once a root has been bracketed, a refinement process is used to
narrow down the time interval within which the root must lie.
This refinement process terminates when the location of the root
has been determined to within an error margin called the
"convergence tolerance." The convergence tolerance used by this
routine is set via the parameter SPICE_GF_CNVTOL.
The value of SPICE_GF_CNVTOL is set to a "tight" value so that the
tolerance doesn't limit the accuracy of solutions found by this
routine. In general the accuracy of input data will be the limiting
factor.
The user may change the convergence tolerance from the default
SPICE_GF_CNVTOL value by calling the routine gfstol_c, e.g.
gfstol_c( tolerance value in seconds )
Call gfstol_c prior to calling this routine. All subsequent
searches will use the updated tolerance value.
Searches over time windows of long duration may require use of
larger tolerance values than the default: the tolerance must be
large enough so that it, when added to or subtracted from the
confinement window's lower and upper bounds, yields distinct time
values.
Setting the tolerance tighter than SPICE_GF_CNVTOL is unlikely to be
useful, since the results are unlikely to be more accurate.
Making the tolerance looser will speed up searches somewhat,
since a few convergence steps will be omitted. However, in most
cases, the step size is likely to have a much greater effect
on processing time than would the convergence tolerance.
The Confinement Window
======================
The simplest use of the confinement window is to specify a time
interval within which a solution is sought. However, the
confinement window can, in some cases, be used to make searches
more efficient. Sometimes it's possible to do an efficient search
to reduce the size of the time period over which a relatively
slow search of interest must be performed. See the "CASCADE"
example program in gf.req for a demonstration.
-Examples
The numerical results shown for these examples may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: standard.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
de421.bsp Planetary ephemeris
pck00009.tpc Planet orientation and
radii
naif0009.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'de421.bsp',
'pck00009.tpc',
'naif0009.tls' )
\begintext
Example:
Determine the time windows from December 1, 2006 UTC to
January 31, 2007 UTC for which the sun-moon-earth configuration
phase angle satisfies the relation conditions with respect to a
reference value of .57598845 radians (the phase angle at
January 1, 2007 00:00:00.000 UTC, 33.001707 degrees). Also
determine the time windows corresponding to the local maximum and
minimum phase angles, and the absolute maximum and minimum phase
angles during the search interval. The configuration defines the
sun as the illuminator, the moon as the target, and the earth as
the observer.
#include <stdio.h>
#include "SpiceUsr.h"
#define TIMFMT "YYYY MON DD HR:MN:SC.###"
#define NINTVL 5000
#define TIMLEN 41
#define NLOOPS 7
int main()
{
/.
Local variables
./
SpiceChar begstr [ TIMLEN ];
SpiceChar endstr [ TIMLEN ];
SPICEDOUBLE_CELL ( cnfine, 2 );
SPICEDOUBLE_CELL ( result, NINTVL*2 );
SpiceDouble adjust;
SpiceDouble et0;
SpiceDouble et1;
SpiceDouble phaseq;
SpiceDouble refval;
SpiceDouble start;
SpiceDouble step;
SpiceDouble stop;
SpiceInt i;
SpiceInt j;
/.
Define the values for target, observer, illuminator, and
aberration correction.
./
ConstSpiceChar * target = "moon";
ConstSpiceChar * illmn = "sun";
ConstSpiceChar * abcorr = "lt+s";
ConstSpiceChar * obsrvr = "earth";
ConstSpiceChar * relate [NLOOPS] = { "=",
"<",
">",
"LOCMIN",
"ABSMIN",
"LOCMAX",
"ABSMAX",
};
/.
Load kernels.
./
furnsh_c ( "standard.tm" );
/.
Store the time bounds of our search interval in
the confinement window.
./
str2et_c ( "2006 DEC 01", &et0 );
str2et_c ( "2007 JAN 31", &et1 );
wninsd_c ( et0, et1, &cnfine );
/.
Search using a step size of 1 day (in units of seconds).
The reference value is 0.57598845 radians. We're not using the
adjustment feature, so we set ADJUST to zero.
./
step = spd_c();
refval = 0.57598845;
adjust = 0.0;
for ( j = 0; j < NLOOPS; j++ )
{
printf ( "Relation condition: %s\n", relate[j] );
/.
Perform the search. The SPICE window `result' contains
the set of times when the condition is met.
./
gfpa_c ( target, illmn, abcorr, obsrvr,
relate[j], refval, adjust, step,
NINTVL, &cnfine, &result );
/.
Display the results.
./
if ( wncard_c(&result) == 0 )
{
printf ( "Result window is empty.\n\n" );
}
else
{
for ( i = 0; i < wncard_c(&result); i++ )
{
/.
Fetch the endpoints of the Ith interval
of the result window.
./
wnfetd_c ( &result, i, &start, &stop );
phaseq = phaseq_c ( start, target, illmn, obsrvr, abcorr );
timout_c ( start, TIMFMT, TIMLEN, begstr );
printf ( "Start time = %s %16.9f\n", begstr, phaseq );
phaseq = phaseq_c ( stop, target, illmn, obsrvr, abcorr );
timout_c ( stop, TIMFMT, TIMLEN, endstr );
printf ( "Stop time = %s %16.9f\n", endstr, phaseq );
}
printf("\n");
}
}
return ( 0 );
}
The program outputs:
Relation condition: =
Start time = 2006 DEC 02 13:31:34.414 0.575988450
Stop time = 2006 DEC 02 13:31:34.414 0.575988450
Start time = 2006 DEC 07 14:07:55.470 0.575988450
Stop time = 2006 DEC 07 14:07:55.470 0.575988450
Start time = 2006 DEC 31 23:59:59.997 0.575988450
Stop time = 2006 DEC 31 23:59:59.997 0.575988450
Start time = 2007 JAN 06 08:16:25.512 0.575988450
Stop time = 2007 JAN 06 08:16:25.512 0.575988450
Start time = 2007 JAN 30 11:41:32.557 0.575988450
Stop time = 2007 JAN 30 11:41:32.557 0.575988450
Relation condition: <
Start time = 2006 DEC 02 13:31:34.414 0.575988450
Stop time = 2006 DEC 07 14:07:55.470 0.575988450
Start time = 2006 DEC 31 23:59:59.997 0.575988450
Stop time = 2007 JAN 06 08:16:25.512 0.575988450
Start time = 2007 JAN 30 11:41:32.557 0.575988450
Stop time = 2007 JAN 31 00:00:00.000 0.468279091
Relation condition: >
Start time = 2006 DEC 01 00:00:00.000 0.940714974
Stop time = 2006 DEC 02 13:31:34.414 0.575988450
Start time = 2006 DEC 07 14:07:55.470 0.575988450
Stop time = 2006 DEC 31 23:59:59.997 0.575988450
Start time = 2007 JAN 06 08:16:25.512 0.575988450
Stop time = 2007 JAN 30 11:41:32.557 0.575988450
Relation condition: LOCMIN
Start time = 2006 DEC 05 00:16:50.317 0.086121423
Stop time = 2006 DEC 05 00:16:50.317 0.086121423
Start time = 2007 JAN 03 14:18:31.977 0.079899769
Stop time = 2007 JAN 03 14:18:31.977 0.079899769
Relation condition: ABSMIN
Start time = 2007 JAN 03 14:18:31.977 0.079899769
Stop time = 2007 JAN 03 14:18:31.977 0.079899769
Relation condition: LOCMAX
Start time = 2006 DEC 20 14:09:10.392 3.055062862
Stop time = 2006 DEC 20 14:09:10.392 3.055062862
Start time = 2007 JAN 19 04:27:54.600 3.074603891
Stop time = 2007 JAN 19 04:27:54.600 3.074603891
Relation condition: ABSMAX
Start time = 2007 JAN 19 04:27:54.600 3.074603891
Stop time = 2007 JAN 19 04:27:54.600 3.074603891
-Restrictions
1) The kernel files to be used by this routine must be loaded
(normally using the CSPICE routine furnsh_c) before this
routine is called.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
E.D. Wright (JPL)
-Version
-CSPICE Version 1.0.0, 15-JUL-2014 (EDW) (NJB)
-Index_Entries
GF phase angle search
-&
*/
{ /* Begin gfpa_c */
/*
Static local variables
*/
static SpiceInt nw = SPICE_GF_NWPA;
/*
Local variables
*/
doublereal * work;
SpiceInt nBytes;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "gfpa_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2 ( CHK_STANDARD, "gfpa_c", SPICE_DP, cnfine, result );
/*
Initialize the input cells if necessary.
*/
CELLINIT2 ( cnfine, result );
/*
Check the input strings to make sure each pointer is non-null
and each string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "gfpa_c", target );
CHKFSTR ( CHK_STANDARD, "gfpa_c", illmn );
CHKFSTR ( CHK_STANDARD, "gfpa_c", abcorr );
CHKFSTR ( CHK_STANDARD, "gfpa_c", obsrvr );
CHKFSTR ( CHK_STANDARD, "gfpa_c", relate );
/*
Check the workspace size; some mallocs have a violent
dislike for negative allocation amounts. To be safe,
rule out a count of zero intervals as well.
*/
if ( nintvls < 1 )
{
setmsg_c ( "The specified workspace interval count # was "
"less than the minimum allowed value (1)." );
errint_c ( "#", nintvls );
sigerr_c ( "SPICE(VALUEOUTOFRANGE)" );
chkout_c ( "gfpa_c" );
return;
}
/*
Allocate the workspace.
We have `nw' "doublereal" cells, each having cell size 2*nintvls.
Each cell also has a control area containing SPICE_CELL_CTRLSZ
double precision values.
*/
nintvls = nintvls * 2;
nBytes = ( nintvls + SPICE_CELL_CTRLSZ ) * nw * sizeof(SpiceDouble);
work = (doublereal *) alloc_SpiceMemory( nBytes );
if ( !work )
{
setmsg_c ( "Workspace allocation of # bytes failed due to "
"malloc failure" );
errint_c ( "#", nBytes );
sigerr_c ( "SPICE(MALLOCFAILURE)" );
chkout_c ( "gfpa_c" );
return;
}
/*
Let the f2'd routine do the work.
*/
gfpa_ ( ( char * ) target,
( char * ) illmn,
( char * ) abcorr,
( char * ) obsrvr,
( char * ) relate,
( doublereal * ) &refval,
( doublereal * ) &adjust,
( doublereal * ) &step,
( doublereal * ) (cnfine->base),
( integer * ) &nintvls,
( integer * ) &nw,
( doublereal * ) work,
( doublereal * ) (result->base),
( ftnlen ) strlen(target),
( ftnlen ) strlen(illmn),
( ftnlen ) strlen(abcorr),
( ftnlen ) strlen(obsrvr),
( ftnlen ) strlen(relate) );
/*
De-allocate the workspace.
*/
free_SpiceMemory( work );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, result ) ;
}
ALLOC_CHECK;
chkout_c ( "gfpa_c" );
} /* End gfpa_c */
void lmpool_c ( const void * cvals,
SpiceInt lenvals,
SpiceInt n )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
cvals I An array that contains a SPICE text kernel.
lenvals I Length of strings in cvals.
n I The number of entries in cvals.
-Detailed_Input
cvals is an array of strings that contains lines of text
that could serve as a SPICE text kernel. cvals is
declared as follows:
ConstSpiceChar cvals [n][lenvals]
Each string in cvals is null-terminated.
lenvals is the common length of the strings in cvals,
including the terminating nulls.
n is the number of strings in cvals.
-Detailed_Output
None.
-Parameters
None.
-Exceptions
1) If the input string pointer is null, the error SPICE(NULLPOINTER)
will be signaled.
2) If the input string length lenvals is not at least 2, the error
SPICE(STRINGTOOLSHORT) will be signaled.
3) The error 'SPICE(BADVARNAME)' signals if a kernel pool
variable name length exceeds 32.
4) Other exceptions are diagnosed by routines in the call tree of
this routine.
-Files
None.
-Particulars
This routine allows you to store a text kernel in an internal
array of your program and load this array into the kernel pool
without first storing its contents as a text kernel.
Kernel pool variable names are restricted to a length of 32
characters or less.
-Examples
Suppose that your application is not particularly sensitive
to the current number of leapseconds but that you would
still like to use a relatively recent leapseconds kernel
without requiring users to load a leapseconds kernel into
the program. The example below shows how you might set up
the initialization portion of your program.
#include "SpiceUsr.h"
#define LNSIZE 81
#define NLINES 27
SpiceChar textbuf[NLINES][LNSIZE] =
{
"DELTET/DELTA_T_A = 32.184",
"DELTET/K = 1.657D-3",
"DELTET/EB = 1.671D-2",
"DELTET/M = ( 6.239996 1.99096871D-7 )",
"DELTET/DELTA_AT = ( 10, @1972-JAN-1",
" 11, @1972-JUL-1",
" 12, @1973-JAN-1",
" 13, @1974-JAN-1",
" 14, @1975-JAN-1",
" 15, @1976-JAN-1",
" 16, @1977-JAN-1",
" 17, @1978-JAN-1",
" 18, @1979-JAN-1",
" 19, @1980-JAN-1",
" 20, @1981-JUL-1",
" 21, @1982-JUL-1",
" 22, @1983-JUL-1",
" 23, @1985-JUL-1",
" 24, @1988-JAN-1",
" 25, @1990-JAN-1",
" 26, @1991-JAN-1",
" 27, @1992-JUL-1",
" 28, @1993-JUL-1",
" 29, @1994-JUL-1",
" 30, @1996-JAN-1",
" 31, @1997-JUL-1",
" 32, @1999-JAN-1 )"
};
lmpool_c ( textbuf, LNSIZE, NLINES );
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
W.L. Taber (JPL)
-Version
-CSPICE Version 1.3.1, 10-FEB-2010 (EDW)
Added mention of the restriction on kernel pool variable
names to 32 characters or less.
-CSPICE Version 1.3.0, 12-JUL-2002 (NJB)
Call to C2F_CreateStrArr_Sig replaced with call to C2F_MapStrArr.
-CSPICE Version 1.2.0, 28-AUG-2001 (NJB)
Const-qualified input array.
-CSPICE Version 1.1.0, 14-FEB-2000 (NJB)
Calls to C2F_CreateStrArr replaced with calls to error-signaling
version of this routine: C2F_CreateStrArr_Sig.
-CSPICE Version 1.0.0, 08-JUN-1999 (NJB) (WLT)
-Index_Entries
Load the kernel pool from an internal text buffer
-&
*/
{ /* Begin lmpool_c */
/*
Local variables
*/
SpiceChar * fCvalsArr;
SpiceInt fCvalsLen;
/*
Participate in error tracing.
*/
chkin_c ( "lmpool_c" );
/*
Make sure the input string pointer is non-null and that the
length lenvals is sufficient.
*/
CHKOSTR ( CHK_STANDARD, "lmpool_c", cvals, lenvals );
/*
Create a Fortran-style string array.
*/
C2F_MapStrArr ( "lmpool_c", n, lenvals, cvals, &fCvalsLen, &fCvalsArr );
if ( failed_c() )
{
chkout_c ( "lmpool_c" );
return;
}
/*
Call the f2c'd routine.
*/
lmpool_ ( ( char * ) fCvalsArr,
( integer * ) &n,
( ftnlen ) fCvalsLen );
/*
Free the dynamically allocated array.
*/
free ( fCvalsArr );
chkout_c ( "lmpool_c" );
} /* End lmpool_c */
SpiceBoolean wnreld_c ( SpiceCell * a,
ConstSpiceChar * op,
SpiceCell * b )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
a I First window.
op I Comparison operator.
b I Second window.
The function returns the result of comparison: a (op) b.
-Detailed_Input
a,
b are CSPICE windows, each of which contains zero or more
intervals.
a and b must be declared as double precision SpiceCells.
op is a comparison operator, indicating the way in
which the input sets are to be compared. op may
be any of the following:
Operator Meaning
-------- -------------------------------------
"=" a = b is SPICETRUE if a and b are equal
(contain the same intervals).
"<>" a <> b is SPICETRUE if a and b are not
equal.
"<=" a <= b is SPICETRUE if a is a subset of b.
"<" a < b is SPICETRUE is a is a proper subset
of b.
">=" a >= b is SPICETRUE if b is a subset of a.
">" a > b is SPICETRUE if b is a proper subset
of a.
-Detailed_Output
The function returns the result of the comparison.
-Parameters
None.
-Exceptions
1) If any of the function arguments are SpiceCells of type
other than double precision, the error SPICE(TYPEMISMATCH)
is signaled.
2) If the relational operator is not recognized, the error
SPICE(INVALIDOPERATION) is signaled.
3) The error SPICE(EMPTYSTRING) is signaled if the input operator
string does not contain at least one character, since the
input string cannot be converted to a Fortran-style string
in this case.
4) The error SPICE(NULLPOINTER) is signalled if the input operator
string pointer is null.
-Files
None.
-Particulars
This function returns SPICETRUE whenever the specified relationship
between the input windows a and b is satisfied. For example,
the expression
wnreld_c ( &needed, "<=", &avail )
is SPICETRUE whenever the window needed is a subset of the window
avail. One window is a subset of another window if each of
the intervals in the first window is included in one of the
intervals in the second window. In addition, the first window
is a proper subset of the second if the second window contains
at least one point not contained in the first window. (Thus,
"<" implies "<=", and ">" implies ">=".)
The following pairs of expressions are equivalent.
wnreld_c ( &a, ">", &b );
wnreld_c ( &b, "<", &a );
wnreld_c ( &a, ">=", &b );
wnreld_c ( &b, "<=", &a );
-Examples
Let a contain the intervals
[ 1, 3 ] [ 7, 11 ] [ 23, 27 ]
Let b and c contain the intervals
[ 1, 2 ] [ 9, 9 ] [ 24, 27 ]
Let d contain the intervals
[ 5, 10 ] [ 15, 25 ]
Finally, let e and f be empty windows (containing no intervals).
Because b and c contain the same intervals,
wnreld_c ( &b, "=", &c )
wnreld_c ( &b, "<=", &c )
wnreld_c ( &b, ">=", &c )
are all SPICETRUE, while
wnreld_c ( &b, "<>", &c )
is SPICEFALSE. Because neither b nor c contains any points not also
contained by the other, neither is a proper subset of the other.
Thus,
wnreld_c ( &b, "<", &c )
wnreld_c ( &b, ">", &c )
are both SPICEFALSE.
Every point contained in b and c is also contained in a. Thus,
wnreld_c ( &b, "<=", &a )
wnreld_c ( &a, ">=", &c )
are both SPICETRUE. In addition, a contains points not contained in
b and c. (That is, the differences a-b and a-c are not empty.)
Thus, b and c are peoper subsets of a as well, and
wnreld_c ( &b, "<", &a )
wnreld_c ( &a, ">", &b )
are both SPICETRUE.
Although a and d have points in common, neither contains the
other. Thus
wnreld_c ( &a, "=", &d )
wnreld_c ( &a, "<=", &d )
wnreld_c ( &a, ">=", &d )
are all SPICEFALSE.
In addition, any window is equal to itself, a subset of itself,
and a superset of itself. Thus,
wnreld_c ( &a, "=", &a )
wnreld_c ( &a, "<=", &a )
wnreld_c ( &a, ">=", &a )
are always SPICETRUE. However, no window is a proper subset or a
proper superset of itself. Thus,
wnreld_c ( &a, "<", &a )
wnreld_c ( &a, ">", &a )
are always SPICEFALSE.
Finally, an empty window is a proper subset of any window
except another empty window. Thus,
wnreld_c ( &e, "<", &a )
is SPICETRUE, but
wnreld_c ( &e, "<", &f )
is SPICEFALSE.
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
H.A. Neilan (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
-Version
-CSPICE Version 1.0.0, 27-JUL-2002 (NJB) (HAN) (WLT) (IMU)
-Index_Entries
compare two d.p. windows
-&
*/
{ /* Begin wnreld_c */
/*
Local variables
*/
SpiceBoolean retval;
/*
Participate in error tracing.
*/
if ( failed_c() )
{
return ( SPICEFALSE );
}
chkin_c ( "wnreld_c" );
/*
Check the input string str to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR_VAL ( CHK_STANDARD, "wnreld_c", op, SPICEFALSE );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2_VAL ( CHK_STANDARD,
"wnreld_c", SPICE_DP, a, b, SPICEFALSE );
/*
Initialize the cells if necessary.
*/
CELLINIT2 ( a, b );
/*
Let the f2c'd routine do the work.
*/
retval = wnreld_ ( (doublereal * ) (a->base),
(char * ) op,
(doublereal * ) (b->base),
(ftnlen ) strlen(op) );
chkout_c ( "wnreld_c" );
return ( retval );
} /* End wnreld_c */
void ekaclc_c ( SpiceInt handle,
SpiceInt segno,
ConstSpiceChar * column,
SpiceInt vallen,
const void * cvals,
ConstSpiceInt * entszs,
ConstSpiceBoolean * nlflgs,
ConstSpiceInt * rcptrs,
SpiceInt * wkindx )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
handle I EK file handle.
segno I Number of segment to add column to.
column I Column name.
vallen I Length of character values.
cvals I Character values to add to column.
entszs I Array of sizes of column entries.
nlflgs I Array of null flags for column entries.
rcptrs I Record pointers for segment.
wkindx I-O Work space for column index.
-Detailed_Input
handle the handle of an EK file that is open for writing.
A "begin segment for fast write" operation must
have already been performed for the designated
segment.
segno is the number of the segment to which data is to be
added. Segments are numbered from 0 to nseg-1, where
nseg is the count of segments in the file.
column is the name of the column to be added. All of
the data for the named column will be added in
one shot.
vallen is the length of the strings in the cvals array.
The array should be declared with dimensions
[nrows][vallen]
where nrows is the number of rows in the column.
cvals is an array containing the entire set of column
entries for the specified column. The entries
are listed in row-order: the column entry for the
first row of the segment is first, followed by the
column entry for the second row, and so on. The
number of column entries must match the declared
number of rows in the segment. For columns having
fixed-size entries, a null entry must be allocated
the same amount of space occupied by a non-null
entry in the array cvals. For columns having
variable-size entries, null entries do not require
any space in the cvals* array, but in any case must
have their allocated space described correctly by
the corresponding element of the entszs array
(described below).
entszs is an array containing sizes of column entries.
The Ith element of entszs gives the size of the
Ith column entry. entszs is used only for columns
having variable-size entries. For such columns,
the dimension of entszs must be at least nrows.
The size of null entries should be set to zero.
For columns having fixed-size entries, the
dimension of this array may be any positive value.
nlflgs is an array of logical flags indicating whether
the corresponding entries are null. If the Ith
element of nlflgs is SPICEFALSE, the Ith column entry
defined by cvals and entszs is added to the
current segment in the specified kernel file.
If the Ith element of nlfgls is SPICETRUE, the
contents of the Ith column entry are undefined.
nlflgs is used only for columns that allow null
values; it's ignored for other columns.
rcptrs is an array of record pointers for the input
segment. This array is obtained as an output
from ekifld_c, the routine called to initiate a
fast write.
wkindx is a work space array used for building a column
index. If the column is indexed, the dimension of
wkindx_c must be at nrows, where nrows is the number
of rows in the column. If the column is not
indexed, this work space is not used, so the
dimension may be any positive value.
-Detailed_Output
None. See $Particulars for a description of the effect of this
routine.
-Parameters
None.
-Exceptions
1) If handle is invalid, the error will be diagnosed by routines
called by this routine.
2) If column is not the name of a declared column, the error
SPICE(NOCOLUMN) will be signaled.
3) If column specifies a column of whose data type is not
character, the error SPICE(WRONGDATATYPE) will be
signalled.
4) If the specified column already contains ANY entries, the
error will be diagnosed by routines called by this routine.
5) If an I/O error occurs while reading or writing the indicated
file, the error will be diagnosed by routines called by this
routine.
6) If the string pointer for column is null, the error
SPICE(NULLPOINTER) will be signaled.
7) If the input string column has length zero, the error
SPICE(EMPTYSTRING) will be signaled.
8) If the string pointer for cvals is null, the error
SPICE(NULLPOINTER) will be signaled.
9) If the string length vallen is less than 2, the error
SPICE(STRINGTOOSHORT) will be signaled.
-Files
See the EK Required Reading for a discussion of the EK file
format.
-Particulars
This routine operates by side effects: it modifies the named
EK file by adding data to the specified column. This routine
writes the entire contents of the specified column in one shot.
This routine creates columns much more efficiently than can be
done by sequential calls to ekacec_c, but has the drawback that
the caller must use more memory for the routine's inputs. This
routine cannot be used to add data to a partially completed
column.
-Examples
1) Suppose we have an E-kernel named order_db.ek which contains
records of orders for data products. The E-kernel has a
table called DATAORDERS that consists of the set of columns
listed below:
DATAORDERS
Column Name Data Type
----------- ---------
ORDER_ID INTEGER
CUSTOMER_ID INTEGER
LAST_NAME CHARACTER*(*)
FIRST_NAME CHARACTER*(*)
ORDER_DATE TIME
COST DOUBLE PRECISION
The order database also has a table of items that have been
ordered. The columns of this table are shown below:
DATAITEMS
Column Name Data Type
----------- ---------
ITEM_ID INTEGER
ORDER_ID INTEGER
ITEM_NAME CHARACTER*(*)
DESCRIPTION CHARACTER*(*)
PRICE DOUBLE PRECISION
We'll suppose that the file ORDER_DB.EK contains two segments,
the first containing the DATAORDERS table and the second
containing the DATAITEMS table.
Below, we show how we'd open a new EK file and create the
first of the segments described above.
#include "SpiceUsr.h"
#include <stdio.h>
void main()
{
/.
Constants
./
#define CNMLEN ( CSPICE_EK_COL_NAM_LEN + 1 )
#define DECLEN 201
#define EKNAME "order_db.ek"
#define FNMLEN 50
#define IFNAME "Test EK/Created 20-SEP-1995"
#define LNMLEN 50
#define LSK "leapseconds.ker"
#define NCOLS 6
#define NRESVC 0
#define NROWS 9
#define TABLE "DATAORDERS"
#define TNMLEN CSPICE_EK_TAB_NAM_LEN
#define UTCLEN 30
/.
Local variables
./
SpiceBoolean nlflgs [ NROWS ];
SpiceChar cdecls [ NCOLS ] [ DECLEN ];
SpiceChar cnames [ NCOLS ] [ CNMLEN ];
SpiceChar fnames [ NROWS ] [ FNMLEN ];
SpiceChar lnames [ NROWS ] [ LNMLEN ];
SpiceChar dateStr [ UTCLEN ];
SpiceDouble costs [ NROWS ];
SpiceDouble ets [ NROWS ];
SpiceInt cstids [ NROWS ];
SpiceInt ordids [ NROWS ];
SpiceInt handle;
SpiceInt i;
SpiceInt rcptrs [ NROWS ];
SpiceInt segno;
SpiceInt sizes [ NROWS ];
SpiceInt wkindx [ NROWS ];
/.
Load a leapseconds kernel for UTC/ET conversion.
./
furnsh_c ( LSK );
/.
Open a new EK file. For simplicity, we will not
reserve any space for the comment area, so the
number of reserved comment characters is zero.
The constant IFNAME is the internal file name.
./
ekopn_c ( EKNAME, IFNAME, NRESVC, &handle );
/.
Set up the table and column names and declarations
for the DATAORDERS segment. We'll index all of
the columns. All columns are scalar, so we omit
the size declaration. Only the COST column may take
null values.
./
strcpy ( cnames[0], "ORDER_ID" );
strcpy ( cdecls[0], "DATATYPE = INTEGER, INDEXED = TRUE" );
strcpy ( cnames[1], "CUSTOMER_ID" );
strcpy ( cdecls[1], "DATATYPE = INTEGER, INDEXED = TRUE" );
strcpy ( cnames[2], "LAST_NAME" );
strcpy ( cdecls[2], "DATATYPE = CHARACTER*(*),"
"INDEXED = TRUE" );
strcpy ( cnames[3], "FIRST_NAME" );
strcpy ( cdecls[3], "DATATYPE = CHARACTER*(*),"
"INDEXED = TRUE" );
strcpy ( cnames[4], "ORDER_DATE" );
strcpy ( cdecls[4], "DATATYPE = TIME, INDEXED = TRUE" );
strcpy ( cnames[5], "COST" );
strcpy ( cdecls[5], "DATATYPE = DOUBLE PRECISION,"
"INDEXED = TRUE,"
"NULLS_OK = TRUE" );
/.
Start the segment. We presume the number of rows
of data is known in advance.
./
ekifld_c ( handle, TABLE, NCOLS, NROWS, CNMLEN,
cnames, DECLEN, cdecls, &segno, rcptrs );
/.
At this point, arrays containing data for the
segment's columns may be filled in. The names
of the data arrays are shown below.
Column Data array
"ORDER_ID" ordids
"CUSTOMER_ID" cstids
"LAST_NAME" lnames
"FIRST_NAME" fnames
"ORDER_DATE" odates
"COST" costs
The null flags array indicates which entries are null.
It is ignored for columns that don't allow null
values. In this case, only the COST column allows
nulls.
Fill in data arrays and null flag arrays here. This code
section would normally be replaced by calls to user functions
returning column values.
./
for ( i = 0; i < NROWS; i++ )
{
ordids[i] = i;
cstids[i] = i*100;
costs [i] = (SpiceDouble) 100*i;
sprintf ( fnames[i], "Order %d Customer first name", i );
sprintf ( lnames[i], "Order %d Customer last name", i );
sprintf ( dateStr, "1998 Mar %d", i );
utc2et_c ( dateStr, ets+i );
nlflgs[i] = SPICEFALSE;
}
nlflgs[1] = SPICETRUE;
/.
The sizes array shown below is ignored for scalar
and fixed-size array columns, so we need not
initialize it. For variable-size arrays, the
Ith element of the sizes array must contain the size
of the Ith column entry in the column being written.
Normally, the sizes array would be reset for each
variable-size column.
Add the columns of data to the segment. All of the
data for each column is written in one shot.
./
ekacli_c ( handle, segno, "order_id", ordids,
sizes, nlflgs, rcptrs, wkindx );
ekacli_c ( handle, segno, "customer_id", cstids,
sizes, nlflgs, rcptrs, wkindx );
ekaclc_c ( handle, segno, "last_name", LNMLEN,
lnames, sizes, nlflgs, rcptrs, wkindx );
ekaclc_c ( handle, segno, "first_name", FNMLEN,
fnames, sizes, nlflgs, rcptrs, wkindx );
ekacld_c ( handle, segno, "order_date", ets,
sizes, nlflgs, rcptrs, wkindx );
ekacld_c ( handle, segno, "cost", costs,
sizes, nlflgs, rcptrs, wkindx );
/.
Complete the segment. The rcptrs array is that
returned by ekifld_c.
./
ekffld_c ( handle, segno, rcptrs );
/.
At this point, the second segment could be
created by an analogous process. In fact, the
second segment could be created at any time; it is
not necessary to populate the first segment with
data before starting the second segment.
The file must be closed by a call to ekcls_c.
./
ekcls_c ( handle );
}
-Restrictions
1) Only one segment can be created at a time using the fast
write routines.
2) No other EK operation may interrupt a fast write. For
example, it is not valid to issue a query while a fast write
is in progress.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.2.2, 14-AUG-2006 (EDW)
Replace mention of ldpool_c with furnsh_c.
-CSPICE Version 1.2.1, 09-JAN-2002 (NJB)
Documentation change: instances of the phrase "fast load"
were replaced with "fast write."
Const-qualified input array cvals.
-CSPICE Version 1.1.0, 12-JUL-1998 (NJB)
Bug fix: now counts elements rather than rows for vector-valued
columns.
Bug fix: now uses dynamically allocated array of type logical
to interface with underlying f2c'd function ekaclc_.
Now maps segno from C to Fortran range.
Added "undef" of masking macro. Changed input pointer types
to pointers to const objects.
Replaced eksdsc_ call with ekssum_c call. This removes unsightly
references to segment descriptor alignments.
Fixed some chkout_c calls which referenced ekifld_c.
-CSPICE Version 1.0.0, 25-FEB-1999 (NJB)
Based on SPICELIB Version 1.0.0, 08-NOV-1995 (NJB)
-Index_Entries
write entire character column to EK segment
-&
*/
{ /* Begin ekaclc_c */
/*
Local variables
*/
SpiceBoolean fnd;
logical * logicalFlags;
SpiceEKSegSum summary;
SpiceChar ** cvalsPtr;
SpiceChar * fCvalsArr;
SpiceInt i;
SpiceInt fCvalsLen;
SpiceInt fSegno;
SpiceInt ncols;
SpiceInt nelts;
SpiceInt nrows;
SpiceInt size;
/*
Participate in error tracing.
*/
chkin_c ( "ekaclc_c" );
/*
Check the column name to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "ekaclc_c", column );
/*
Check the value array to make sure the pointer is non-null
and the string length is non-zero. Note: this check is normally
done for output strings: CHKOSTR is the macro that does the job.
*/
CHKOSTR ( CHK_STANDARD, "ekaclc_c", cvals, vallen );
/*
Get the row count for this segment.
*/
ekssum_c ( handle, segno, &summary );
nrows = summary.nrows;
/*
Locate the index of this column in the segment descriptor.
*/
ncols = summary.ncols;
i = 0;
fnd = SPICEFALSE;
while ( ( i < ncols ) && ( !fnd ) )
{
if ( eqstr_c( column, summary.cnames[i] ) )
{
fnd = SPICETRUE;
}
else
{
i++;
}
}
if ( !fnd )
{
setmsg_c ( "Column <#> does not belong to segment #. " );
errch_c ( "#", column );
errint_c ( "#", segno );
sigerr_c ( "SPICE(NOCOLUMN)" );
chkout_c ( "ekaclc_c" );
return;
}
/*
Now i is the index within the segment descriptor of the column
descriptor for the column of interest. Get the dimension information
for this column.
*/
size = summary.cdescrs[i].size;
/*
Compute the total string count of the input array. If the column
has fixed-size entries, we ignore the entszs array. Otherwise, the
entszs array tells us how many strings we're getting.
*/
if ( size == SPICE_EK_VARSIZ )
{
nelts = sumai_c ( entszs, nrows );
}
else
{
nelts = nrows * size;
}
/*
Allocate an array of logicals and assign values from the input
array of SpiceBooleans.
*/
logicalFlags = ( logical * ) malloc ( nelts * sizeof(logical) );
if ( !logicalFlags )
{
setmsg_c ( "Failure on malloc call to create null flag array "
"for column values." );
sigerr_c ( "SPICE(MALLOCFAILED)" );
chkout_c ( "ekaclc_c" );
return;
}
/*
Copy the input null flags to our array of type logical.
*/
for ( i = 0; i < nrows; i++ )
{
logicalFlags[i] = nlflgs[i];
}
/*
We need to make a blank-padded version of the cvals array.
We'll first allocate an array of character pointers to index
the values, initialize this array, and use it to produce
a dynamically allocated array of Fortran-style strings.
*/
cvalsPtr = ( SpiceChar ** ) malloc ( nelts * sizeof(SpiceChar *) );
if ( cvalsPtr == 0 )
{
free ( logicalFlags );
setmsg_c ( "Failure on malloc call to create pointer array "
"for column values." );
sigerr_c ( "SPICE(MALLOCFAILED)" );
chkout_c ( "ekaclc_c" );
return;
}
for ( i = 0; i < nelts; i++ )
{
cvalsPtr[i] = (SpiceChar *)cvals + ( i * vallen );
}
C2F_CreateFixStrArr ( nelts,
vallen,
( ConstSpiceChar ** ) cvalsPtr,
&fCvalsLen,
&fCvalsArr );
if ( failed_c() )
{
free ( logicalFlags );
free ( cvalsPtr );
chkout_c ( "ekaclc_c" );
return;
}
/*
Map the segment number to the Fortran range.
*/
fSegno = segno + 1;
ekaclc_ ( ( integer * ) &handle,
( integer * ) &fSegno,
( char * ) column,
( char * ) fCvalsArr,
( integer * ) entszs,
( logical * ) logicalFlags,
( integer * ) rcptrs,
( integer * ) wkindx,
( ftnlen ) strlen(column),
( ftnlen ) fCvalsLen );
/*
Clean up all of our dynamically allocated arrays.
*/
free ( cvalsPtr );
free ( fCvalsArr );
free ( logicalFlags );
chkout_c ( "ekaclc_c" );
} /* End ekaclc_c */
//------------------------------------------------------------------------------
void SpiceAttitudeKernelReader::GetCoverageStartAndEnd(StringArray &kernels,
Integer forNaifId,
Real &start,
Real &end,
bool needAngVel)
{
// first check to see if a kernel specified is not loaded; if not,
// try to load it
for (unsigned int ii = 0; ii < kernels.size(); ii++)
if (!IsLoaded(kernels.at(ii))) LoadKernel(kernels.at(ii));
SpiceInt idSpice = forNaifId;
SpiceInt arclen = 4;
SpiceInt typlen = 5;
bool firstInt = true;
bool idOnKernel = false;
char kStr[5] = " ";
char aStr[4] = " ";
char levelStr[8] = "SEGMENT";
char timeStr[4] = "TDB";
SpiceBoolean needAv = needAngVel;
ConstSpiceChar *kernelName = NULL;
ConstSpiceChar *level = levelStr;
ConstSpiceChar *timeSys = timeStr;
SpiceDouble tol = 0.0;
SpiceInt objId = 0;
SpiceInt numInt = 0;
SpiceChar *kernelType;
SpiceChar *arch;
SpiceDouble b;
SpiceDouble e;
Real bA1;
Real eA1;
SPICEINT_CELL(ids, 200);
SPICEDOUBLE_CELL(cover, 200000);
// look through each kernel
for (unsigned int ii = 0; ii < kernels.size(); ii++)
{
#ifdef DEBUG_CK_COVERAGE
MessageInterface::ShowMessage(wxT("Checking coverage for ID %d on kernel %s\n"),
forNaifId, (kernels.at(ii)).c_str());
#endif
kernelName = kernels[ii].char_str();
// check the type of kernel
arch = aStr;
kernelType = kStr;
getfat_c(kernelName, arclen, typlen, arch, kernelType);
if (failed_c())
{
ConstSpiceChar option[] = "LONG";
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
SpiceChar err[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii( err));
wxString errmsg = wxT("Error determining type of kernel \"");
errmsg += kernels.at(ii) + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
throw UtilityException(errmsg);
}
#ifdef DEBUG_CK_COVERAGE
MessageInterface::ShowMessage(wxT("Kernel is of type %s\n"),
kernelType);
#endif
// only deal with CK kernels
if (eqstr_c(kernelType, "ck") || eqstr_c(kernelType, "CK"))
{
ckobj_c(kernelName, &ids);
// get the list of objects (IDs) for which data exists in the CK kernel
for (SpiceInt jj = 0; jj < card_c(&ids); jj++)
{
objId = SPICE_CELL_ELEM_I(&ids,jj);
#ifdef DEBUG_CK_COVERAGE
MessageInterface::ShowMessage(wxT("Kernel contains data for object %d\n"),
(Integer) objId);
#endif
// look to see if this kernel contains data for the object we're interested in
if (objId == idSpice)
{
idOnKernel = true;
break;
}
// if (objId == (idSpice * 1000))
// {
// idSpice = idSpice * 1000;
// naifIDSPICE = idSpice; // not the way to do this - should pass it back
// idOnKernel = true;
// break;
// }
}
// only deal with kernels containing data for the object we're interested in
if (idOnKernel)
{
#ifdef DEBUG_CK_COVERAGE
MessageInterface::ShowMessage(wxT("Checking kernel %s for data for object %d\n"),
(kernels.at(ii)).c_str(), (Integer) objId);
#endif
scard_c(0, &cover); // reset the coverage cell
ckcov_c (kernelName, idSpice, needAv, level, tol, timeSys, &cover);
if (failed_c())
{
ConstSpiceChar option[] = "LONG";
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
SpiceChar err[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error determining coverage for CK kernel \"");
errmsg += kernels.at(ii) + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
throw UtilityException(errmsg);
}
numInt = wncard_c(&cover);
#ifdef DEBUG_CK_COVERAGE
MessageInterface::ShowMessage(wxT("Number of intervals found = %d\n"),
(Integer) numInt);
#endif
if ((firstInt) && (numInt > 0))
{
wnfetd_c(&cover, 0, &b, &e);
if (failed_c())
{
ConstSpiceChar option[] = "LONG";
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
SpiceChar err[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error getting interval times for CK kernel \"");
errmsg += kernels.at(ii) + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
throw UtilityException(errmsg);
}
start = SpiceTimeToA1(b);
end = SpiceTimeToA1(e);
firstInt = false;
}
for (SpiceInt jj = 0; jj < numInt; jj++)
{
wnfetd_c(&cover, jj, &b, &e);
bA1 = SpiceTimeToA1(b);
eA1 = SpiceTimeToA1(e);
if (bA1 < start) start = bA1;
if (eA1 > end) end = eA1;
}
}
}
}
if (firstInt)
{
char itsName[256];
SpiceChar *itsNameSPICE = itsName;
SpiceBoolean found2;
bodc2n_c(naifIDSPICE, 256, itsNameSPICE, &found2);
if (found2 == SPICEFALSE)
{
wxString errmsg = wxT("Error - unable to find name for body in SPICE kernel pool");
throw UtilityException(errmsg);
}
else
{
wxString nameStr = wxString::FromAscii(itsNameSPICE);
wxString errmsg = wxT("Error - no data available for body ");
errmsg += nameStr + wxT(" on specified CK kernels");
throw UtilityException(errmsg);
}
}
}
//---------------------------------------------------------------------------
void SpiceAttitudeKernelReader::GetTargetOrientation(const wxString &objectName,
Integer naifID,
Integer forFrameNaifId,
const A1Mjd &atTime,
// Real tolerance,
Rmatrix33 &r33,
Rvector3 &angVel,
const wxString &referenceFrame)
{
#ifdef DEBUG_CK_READING
MessageInterface::ShowMessage(wxT("Entering GetTargetOrientation for object %s, with NAIF ID %d, at time %12.10f, with frame = %s\n"),
objectName.c_str(), naifID, atTime.Get(), referenceFrame.c_str());
#endif
wxString objectNameToUse = objectName;
objectNameToUse = GmatStringUtil::ToUpper(objectNameToUse);
objectNameSPICE = objectNameToUse.char_str();
naifIDSPICE = naifID;
frameNaifIDSPICE = forFrameNaifId;
referenceFrameSPICE = referenceFrame.char_str();
etSPICE = A1ToSpiceTime(atTime.Get());
// boddef_c(objectNameSPICE, naifIDSPICE); // CSPICE method to set NAIF ID for an object - is this valid for spacecraft?
// Convert the time (in TDB) to spacecaft ticks
SpiceDouble scTime;
sce2c_c(naifIDSPICE, etSPICE, &scTime);
if (failed_c())
{
ConstSpiceChar option[] = "LONG"; // retrieve long error message, for now
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error getting spacecraft time (ticks) for object \"");
errmsg += objectName + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
// get the tolerance in spacecraft clock ticks
wxString tolerance = wxT("01"); // this should probably be user input, or set as a constant
ConstSpiceChar *tol = tolerance.char_str();
SpiceDouble tolTicks;
sctiks_c(naifIDSPICE, tol, &tolTicks);
if (failed_c())
{
ConstSpiceChar option[] = "LONG"; // retrieve long error message, for now
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error getting tolerance (ticks) for object \"");
errmsg += objectName + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
#ifdef DEBUG_CK_READING
MessageInterface::ShowMessage(wxT("First, check for coverage for object \"%s\", with NAIF ID %d\n"),
objectName.c_str(), naifID);
#endif
Real beginCov = 0.0;
Real endCov = 0.0;
GetCoverageStartAndEnd(loadedKernels, forFrameNaifId, beginCov, endCov, false);
// Now get the C-matrix and angular velocity at the requested time
SpiceDouble cmat[3][3];
SpiceDouble av[3];
SpiceBoolean found;
SpiceDouble clkout;
#ifdef DEBUG_CK_READING
MessageInterface::ShowMessage(wxT("about to call ckgpav: \n"));
MessageInterface::ShowMessage(wxT(" NAIF ID = %d\n")
wxT(" etSPICE = %12.10f\n")
wxT(" scTime = %12.10fn")
wxT(" tolTicks = %12.10f\n")
wxT(" refFrame = %s\n"),
(Integer) naifIDSPICE, (Real) etSPICE, (Real) scTime, (Real) tolTicks,
referenceFrame.c_str());
#endif
ckgpav_c(frameNaifIDSPICE, scTime, tolTicks, referenceFrameSPICE, cmat, av, &clkout, &found);
// ckgpav_c(naifIDSPICE, scTime, tolTicks, referenceFrameSPICE, cmat, av, &clkout, &found);
if (failed_c())
{
ConstSpiceChar option[] = "LONG"; // retrieve long error message, for now
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error getting C-matrix and/or angular velocity for object \"");
errmsg += objectName + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
if (found == SPICEFALSE)
{
wxString errmsg = wxT("Pointing data for object ");
errmsg += objectName + wxT(" not found on loaded CK/SCLK kernels.\n");
throw UtilityException(errmsg);
}
#ifdef DEBUG_CK_READING
MessageInterface::ShowMessage(wxT("results from ckgpav: \n"));
MessageInterface::ShowMessage(wxT(" cosMat = %12.10f %12.10f %12.10f\n")
wxT(" %12.10f %12.10f %12.10f\n")
wxT(" %12.10f %12.10f %12.10f\n"),
(Real)cmat[0][0], (Real)cmat[0][1], (Real)cmat[0][2],
(Real)cmat[1][0], (Real)cmat[1][1], (Real)cmat[1][2],
(Real)cmat[2][0], (Real)cmat[2][1], (Real)cmat[2][2]);
MessageInterface::ShowMessage(wxT(" angvel = %12.10f %12.10f %12.10f\n"),
(Real)av[0], (Real)av[1], (Real)av[2]);
MessageInterface::ShowMessage(wxT(" and clkout = %12.10f\n"), (Real) clkout);
#endif
// Set output values
r33.Set(cmat[0][0], cmat[0][1], cmat[0][2],
cmat[1][0], cmat[1][1], cmat[1][2],
cmat[2][0], cmat[2][1], cmat[2][2]);
angVel.Set(av[0], av[1], av[2]);
}
void dasac_c ( SpiceInt handle,
SpiceInt n,
SpiceInt buflen,
const void * buffer )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
handle I DAS handle of a file opened with write access.
n I Number of comments to put into the comment area.
buflen I Line length associated with buffer.
buffer I Buffer of lines to be put into the comment area.
-Detailed_Input
handle The file handle of a binary DAS file which has been
opened with write access.
n The number of strings in buffer that are to be
appended to the comment area of the binary DAS file
attached to handle.
buflen is the common length of the strings in buffer, including the
terminating nulls.
buffer A buffer containing comments which are to be added
to the comment area of the binary DAS file attached
to handle. buffer should be declared as follows:
ConstSpiceChar buffer [n][buflen]
Each string in buffer is null-terminated.
-Detailed_Output
None.
-Parameters
None.
-Exceptions
1) If the number of comments to be added is not positive, the
error SPICE(INVALIDARGUMENT) will be signaled.
2) If a non-null, non printing ASCII character is encountered in the
comments, the error SPICE(ILLEGALCHARACTER) will be
signaled.
3) If the binary DAS file attached to handle is not open for
write access, an error will be signaled by a routine called
by this routine.
4) If the input buffer pointer is null, the error SPICE(NULLPOINTER)
will be signaled.
5) If the input buffer string length buflen is not at least 2,
the error SPICE(STRINGTOOSHORT) will be signaled.
-Files
See argument handle in Detailed_Input.
-Particulars
Binary DAS files contain a data area which is reserved for storing
annotations or descriptive textual information about the data
contained in a file. This area is referred to as the "comment
area" of the file. The comment area of a DAS file is a line
oriented medium for storing textual information. The comment
area preserves any leading or embedded white space in the line(s)
of text which are stored so that the appearance of the
information will be unchanged when it is retrieved (extracted) at
some other time. Trailing blanks, however, are NOT preserved,
due to the way that character strings are represented in
standard Fortran 77.
This routine will take a buffer of text lines and add (append)
them to the comment area of a binary DAS file. If there are no
comments in the comment area of the file, then space will be
allocated and the text lines in buffer will then placed into the
comment area. The text lines may contain only printable ASCII
characters (decimal values 32 - 126).
There is no maximum length imposed on the significant portion
of a text line that may be placed into the comment area of a
DAS file. The maximum length of a line stored in the comment
area should be reasonable, however, so that they may be easily
extracted. A good value for this would be 255 characters, as
this can easily accommodate "screen width" lines as well as
long lines which may contain some other form of information.
-Examples
Let
handle be the handle for a DAS file which has been opened
with write access.
n be the number of lines of text to be added to the
comment area of the binary DAS file attached to
handle.
BUFLEN be the declared line length of the buffer.
buffer is a list of text lines to be added to the comment
area of the binary DAS file attached to handle.
The call
dasac_c ( handle, n, BUFLEN, buffer );
will append the first n line(s) in buffer to the comment area
of the binary DAS file attached to handle.
-Restrictions
1) This routine uses constants that are specific to the ASCII
character sequence. The results of using this routine with
a different character sequence are unpredictable.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
K.R. Gehringer (JPL)
-Version
-CSPICE Version 1.1.0, 02-MAR-2003 (NJB)
Added error check in wrapper for non-positive
buffer line count.
-CSPICE Version 1.0.0, 25-FEB-2003 (NJB) (KRG)
-Index_Entries
add comments to a binary das file
append comments to a das file comment area
-&
*/
{ /* Begin dasac_c */
/*
Local variables
*/
SpiceChar * fCvalsArr;
SpiceInt fCvalsLen;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "dasac_c" );
/*
Check the line count of the input buffer.
*/
if ( n < 1 )
{
setmsg_c ( "Comment buffer line count n = #; must be positive." );
errint_c ( "#", n );
sigerr_c ( "SPICE(INVALIDARGUMENT)" );
chkout_c ( "dasac_c" );
return;
}
/*
Check the input buffer for null pointer or short lines.
*/
CHKOSTR ( CHK_STANDARD, "dasac_c", buffer, buflen );
/*
Map the input buffer to a Fortran-style buffer.
*/
C2F_MapStrArr ( "dasac_c", n, buflen, buffer, &fCvalsLen, &fCvalsArr );
if ( failed_c() )
{
chkout_c ( "dasac_c" );
return;
}
/*
Call the f2c'd routine.
*/
dasac_ ( ( integer * ) &handle,
( integer * ) &n,
( char * ) fCvalsArr,
( ftnlen ) fCvalsLen );
/*
Free the dynamically allocated array.
*/
free ( fCvalsArr );
chkout_c ( "dasac_c" );
} /* End dasac_c */
void gfsubc_c ( ConstSpiceChar * target,
ConstSpiceChar * fixref,
ConstSpiceChar * method,
ConstSpiceChar * abcorr,
ConstSpiceChar * obsrvr,
ConstSpiceChar * crdsys,
ConstSpiceChar * coord,
ConstSpiceChar * relate,
SpiceDouble refval,
SpiceDouble adjust,
SpiceDouble step,
SpiceInt nintvls,
SpiceCell * cnfine,
SpiceCell * result )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
SPICE_GF_CNVTOL
P Convergence tolerance.
target I Name of the target body
fixref I Body fixed frame associated with 'target'
method I Name of method type for subpoint calculation
abcorr I Aberration correction flag
obsrvr I Name of the observing body
crdsys I Name of the coordinate system containing 'coord'
coord I Name of the coordinate of interest
relate I Operator that either looks for an extreme value
(max, min, local, absolute) or compares the
coordinate value and refval
refval I Reference value
adjust I Adjustment value for absolute extrema searches
step I Step size used for locating extrema and roots
nintvls I Workspace window interval count
cnfine I-O SPICE window to which the search is restricted
result O SPICE window containing results
-Detailed_Input
target the string name of a target body. Optionally, you may
supply the integer ID code for the object as an
integer string. For example both 'MOON' and '301'
are legitimate strings that indicate the moon is the
target body.
The target and observer define a position vector
that points from the observer to the target.
fixref the string name of the body-fixed, body-centered
reference frame associated with the target body target.
The SPICE frame subsystem must recognize the 'fixref' name.
method the string name of the method to use for the subpoint
calculation. The accepted values for method:
'Near point: ellipsoid' The sub-observer point
computation uses a
triaxial ellipsoid to
model the surface of the
target body. The
sub-observer point is
defined as the nearest
point on the target
relative to the
observer.
'Intercept: ellipsoid' The sub-observer point
computation uses a
triaxial ellipsoid to
model the surface of the
target body. The
sub-observer point is
defined as the target
surface intercept of the
line containing the
observer and the
target's center.
The method string lacks sensitivity to case, embedded, leading
and trailing blanks.
abcorr the string description of the aberration corrections to apply
to the state evaluations to account for one-way light time
and stellar aberration.
This routine accepts the same aberration corrections as does
the SPICE routine SPKEZR. See the header of SPKEZR for a
detailed description of the aberration correction options.
For convenience, the options are listed below:
'NONE' Apply no correction.
'LT' "Reception" case: correct for
one-way light time using a Newtonian
formulation.
'LT+S' "Reception" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
'CN' "Reception" case: converged
Newtonian light time correction.
'CN+S' "Reception" case: converged
Newtonian light time and stellar
aberration corrections.
'XLT' "Transmission" case: correct for
one-way light time using a Newtonian
formulation.
'XLT+S' "Transmission" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
'XCN' "Transmission" case: converged
Newtonian light time correction.
'XCN+S' "Transmission" case: converged
Newtonian light time and stellar
aberration corrections.
The abcorr string lacks sensitivity to case, and to embedded,
leading and trailing blanks.
obsrvr the string naming the observing body. Optionally, you
may supply the ID code of the object as an integer
string. For example, both 'EARTH' and '399' are
legitimate strings to supply to indicate the
observer is Earth.
crdsys the string name of the coordinate system for which the
coordinate of interest is a member.
coord the string name of the coordinate of interest in crdsys.
The supported coordinate systems and coordinate names are:
The supported coordinate systems and coordinate names are:
Coordinate System (CRDSYS) Coordinates (COORD) Range
'RECTANGULAR' 'X'
'Y'
'Z'
'LATITUDINAL' 'RADIUS'
'LONGITUDE' (-Pi,Pi]
'LATITUDE' [-Pi/2,Pi/2]
'RA/DEC' 'RANGE'
'RIGHT ASCENSION' [0,2Pi)
'DECLINATION' [-Pi/2,Pi/2]
'SPHERICAL' 'RADIUS'
'COLATITUDE' [0,Pi]
'LONGITUDE' (-Pi,Pi]
'CYLINDRICAL' 'RADIUS'
'LONGITUDE' [0,2Pi)
'Z'
'GEODETIC' 'LONGITUDE' (-Pi,Pi]
'LATITUDE' [-Pi/2,Pi/2]
'ALTITUDE'
'PLANETOGRAPHIC' 'LONGITUDE' [0,2Pi)
'LATITUDE' [-Pi/2,Pi/2]
'ALTITUDE'
The ALTITUDE coordinates have a constant value
of zero +/- roundoff for ellipsoid targets.
Limit searches for coordinate events in the GEODETIC and
PLANETOGRAPHIC coordinate systems to TARGET bodies with
axial symmetry in the equatorial plane, i.e. equality
of the body X and Y radii (oblate or prolate spheroids).
relate the string or character describing the relational operator
used to define a constraint on the selected coordinate of the
subpoint vector. The result window found by this routine
indicates the time intervals where the constraint is satisfied.
Supported values of relate and corresponding meanings are
shown below:
'>' Separation is greater than the reference
value refval.
'=' Separation is equal to the reference
value refval.
'<' Separation is less than the reference
value refval.
'ABSMAX' Separation is at an absolute maximum.
'ABSMIN' Separation is at an absolute minimum.
'LOCMAX' Separation is at a local maximum.
'LOCMIN' Separation is at a local minimum.
The caller may indicate that the region of interest
is the set of time intervals where the quantity is
within a specified measure of an absolute extremum.
The argument ADJUST (described below) is used to
specify this measure.
Local extrema are considered to exist only in the
interiors of the intervals comprising the confinement
window: a local extremum cannot exist at a boundary
point of the confinement window.
The relate string lacks sensitivity to case, leading
and trailing blanks.
refval the double precision reference value used together with
relate argument to define an equality or inequality to
satisfy by the selected coordinate of the subpoint
vector. See the discussion of relate above for
further information.
The units of refval correspond to the type as defined
by coord, radians for angular measures, kilometers for
distance measures.
adjust a double precision value used to modify searches for
absolute extrema: when 'relate' is set to ABSMAX or ABSMIN and
'adjust' is set to a positive value, gfsubc_c finds times
when the position vector coordinate is within adjust
radians/kilometers of the specified extreme value.
For 'relate' set to ABSMAX, the result window contains
time intervals when the position vector coordinate has
values between ABSMAX - adjust and ABSMAX.
For 'relate' set to ABSMIN, the result window contains
time intervals when the position vector coordinate has
values between ABSMIN and ABSMIN + adjust.
'adjust' is not used for searches for local extrema,
equality or inequality conditions.
step the double precision time step size to use in the search.
step must be short enough for a search using this step
size to locate the time intervals where coordinate function
of the subpoint vector is monotone increasing or
decreasing. However, step must not be *too* short, or
the search will take an unreasonable amount of time.
The choice of step affects the completeness but not
the precision of solutions found by this routine; the
precision is controlled by the convergence tolerance.
step has units of TDB seconds.
nintvls an integer value specifying the number of intervals in the
the internal workspace array used by this routine. 'nintvls'
should be at least as large as the number of intervals
within the search region on which the specified observer-target
vector coordinate function is monotone increasing or decreasing.
It does no harm to pick a value of 'nintvls' larger than the
minimum required to execute the specified search, but if chosen
too small, the search will fail.
cnfine a double precision SPICE window that confines the time
period over which the specified search is conducted.
cnfine may consist of a single interval or a collection
of intervals.
In some cases the confinement window can be used to
greatly reduce the time period that must be searched
for the desired solution. See the Particulars section
below for further discussion.
See the Examples section below for a code example
that shows how to create a confinement window.
-Detailed_Output
cnfine is the input confinement window, updated if necessary
so the control area of its data array indicates the
window's size and cardinality. The window data are
unchanged.
result the SPICE window of intervals, contained within the
confinement window cnfine, on which the specified
constraint is satisfied.
If result is non-empty on input, its contents
will be discarded before gfsubc_c conducts its
search.
result must be declared and initialized with sufficient
size to capture the full set of time intervals
within the search region on which the specified constraint
is satisfied.
If the search is for local extrema, or for absolute
extrema with adjust set to zero, then normally each
interval of result will be a singleton: the left and
right endpoints of each interval will be identical.
If no times within the confinement window satisfy the
constraint, result will be returned with a
cardinality of zero.
-Parameters
SPICE_GF_CNVTOL
is the convergence tolerance used for finding endpoints
of the intervals comprising the result window.
SPICE_GF_CNVTOL is used to determine when binary searches
for roots should terminate: when a root is bracketed
within an interval of length SPICE_GF_CNVTOL; the root is
considered to have been found.
The accuracy, as opposed to precision, of roots found by
this routine depends on the accuracy of the input data.
In most cases, the accuracy of solutions will be inferior
to their precision.
SPICE_GF_CNVTOL has the value 1.0e-6. Units are TDB
seconds.
-Exceptions
1) In order for this routine to produce correct results,
the step size must be appropriate for the problem at hand.
Step sizes that are too large may cause this routine to miss
roots; step sizes that are too small may cause this routine
to run unacceptably slowly and in some cases, find spurious
roots.
This routine does not diagnose invalid step sizes, except
that if the step size is non-positive, an error is signaled
by a routine in the call tree of this routine.
2) Due to numerical errors, in particular,
- Truncation error in time values
- Finite tolerance value
- Errors in computed geometric quantities
it is *normal* for the condition of interest to not always be
satisfied near the endpoints of the intervals comprising the
result window.
The result window may need to be contracted slightly by the
caller to achieve desired results. The SPICE window routine
wncond_c can be used to contract the result window.
3) If an error (typically cell overflow) occurs while performing
window arithmetic, the error will be diagnosed by a routine
in the call tree of this routine.
4) If the relational operator `relate' is not recognized, an
error is signaled by a routine in the call tree of this
routine.
5) If the aberration correction specifier contains an
unrecognized value, an error is signaled by a routine in the
call tree of this routine.
6) If `adjust' is negative, an error is signaled by a routine in
the call tree of this routine.
7) If either of the input body names do not map to NAIF ID
codes, an error is signaled by a routine in the call tree of
this routine.
8) If required ephemerides or other kernel data are not
available, an error is signaled by a routine in the call tree
of this routine.
9) If any input string argument pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
10) If any input string argument is empty, the error
SPICE(EMPTYSTRING) will be signaled.
11) If the workspace interval count 'nintvls' is less than 1, the
error SPICE(VALUEOUTOFRANGE) will be signaled.
12) If the required amount of workspace memory cannot be
allocated, the error SPICE(MALLOCFAILURE) will be
signaled.
-Files
Appropriate SPK and PCK kernels must be loaded by the
calling program before this routine is called.
The following data are required:
- SPK data: the calling application must load ephemeris data
for the targets, observer, and any intermediate objects in
a chain connecting the targets and observer that cover the time
period specified by the window CNFINE. If aberration
corrections are used, the states of target and observer
relative to the solar system barycenter must be calculable
from the available ephemeris data. Typically ephemeris data
are made available by loading one or more SPK files using
FURNSH.
- PCK data: bodies modeled as triaxial ellipsoids must have
semi-axis lengths provided by variables in the kernel pool.
Typically these data are made available by loading a text
PCK file using FURNSH.
- If non-inertial reference frames are used, then PCK
files, frame kernels, C-kernels, and SCLK kernels may be
needed.
Such kernel data are normally loaded once per program
run, NOT every time this routine is called.
-Particulars
This routine provides a simpler, but less flexible interface
than does the routine gfevnt_c for conducting searches for
subpoint position vector coordinate value events.
Applications that require support for progress reporting, interrupt
handling, non-default step or refinement functions, or non-default
convergence tolerance should call gfevnt_c rather than this routine.
This routine determines a set of one or more time intervals
within the confinement window when the selected coordinate of
the subpoint position vector satisfies a caller-specified
constraint. The resulting set of intervals is returned as a SPICE
window.
Below we discuss in greater detail aspects of this routine's
solution process that are relevant to correct and efficient
use of this routine in user applications.
The Search Process
==================
Regardless of the type of constraint selected by the caller, this
routine starts the search for solutions by determining the time
periods, within the confinement window, over which the specified
coordinate function is monotone increasing and monotone
decreasing. Each of these time periods is represented by a SPICE
window. Having found these windows, all of the coordinate
function's local extrema within the confinement window are known.
Absolute extrema then can be found very easily.
Within any interval of these "monotone" windows, there will be at
most one solution of any equality constraint. Since the boundary
of the solution set for any inequality constraint is the set
of points where an equality constraint is met, the solutions of
both equality and inequality constraints can be found easily
once the monotone windows have been found.
Step Size
=========
The monotone windows (described above) are found using a two-step
search process. Each interval of the confinement window is
searched as follows: first, the input step size is used to
determine the time separation at which the sign of the rate of
change of coordinate will be sampled. Starting at
the left endpoint of an interval, samples will be taken at each
step. If a change of sign is found, a root has been bracketed; at
that point, the time at which the time derivative of the coordinate
is zero can be found by a refinement process, for example,
using a binary search.
Note that the optimal choice of step size depends on the lengths
of the intervals over which the coordinate function is monotone:
the step size should be shorter than the shortest of these
intervals (within the confinement window).
The optimal step size is *not* necessarily related to the lengths
of the intervals comprising the result window. For example, if
the shortest monotone interval has length 10 days, and if the
shortest result window interval has length 5 minutes, a step size
of 9.9 days is still adequate to find all of the intervals in the
result window. In situations like this, the technique of using
monotone windows yields a dramatic efficiency improvement over a
state-based search that simply tests at each step whether the
specified constraint is satisfied. The latter type of search can
miss solution intervals if the step size is shorter than the
shortest solution interval.
Having some knowledge of the relative geometry of the target and
observer can be a valuable aid in picking a reasonable step size.
In general, the user can compensate for lack of such knowledge by
picking a very short step size; the cost is increased computation
time.
Note that the step size is not related to the precision with which
the endpoints of the intervals of the result window are computed.
That precision level is controlled by the convergence tolerance.
Convergence Tolerance
=====================
As described above, the root-finding process used by this routine
involves first bracketing roots and then using a search process
to locate them. "Roots" are both times when local extrema are
attained and times when the distance function is equal to a
reference value. All endpoints of the intervals comprising the
result window are either endpoints of intervals of the
confinement window or roots.
Once a root has been bracketed, a refinement process is used to
narrow down the time interval within which the root must lie.
This refinement process terminates when the location of the root
has been determined to within an error margin called the
"convergence tolerance." The convergence tolerance used by this
routine is set by the parameter SPICE_GF_CNVTOL.
The value of SPICE_GF_CNVTOL is set to a "tight" value in the f2c'd
routine so that the tolerance doesn't become the limiting factor
in the accuracy of solutions found by this routine. In general the
accuracy of input data will be the limiting factor.
To use a different tolerance value, a lower-level GF routine such
as gfevnt_c must be called. Making the tolerance tighter than
SPICE_GF_CNVTOL is unlikely to be useful, since the results are unlikely
to be more accurate. Making the tolerance looser will speed up
searches somewhat, since a few convergence steps will be omitted.
However, in most cases, the step size is likely to have a much
greater effect on processing time than would the convergence
tolerance.
The Confinement Window
======================
The simplest use of the confinement window is to specify a time
interval within which a solution is sought. However, the
confinement window can, in some cases, be used to make searches
more efficient. Sometimes it's possible to do an efficient search
to reduce the size of the time period over which a relatively
slow search of interest must be performed.
Practical use of the coordinate search capability would likely
consist of searches over multiple coordinate constraints to find
time intervals that satisfies the constraints. An effective
technique to accomplish such a search is to use the result
window from one search as the confinement window of the next.
Longitude and Right Ascension
=============================
The cyclic nature of the longitude and right ascension coordinates
produces branch cuts at +/- 180 degrees longitude and 0-360
longitude. Round-off error may cause solutions near these branches
to cross the branch. Use of the SPICE routine wncond_c will contract
solution windows by some epsilon, reducing the measure of the
windows and eliminating the branch crossing. A one millisecond
contraction will in most cases eliminate numerical round-off caused
branch crossings.
-Examples
The numerical results shown for these examples may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
The example shown below requires a "standard" set of SPICE
kernels. We list these kernels in a meta kernel named 'standard.tm'.
KPL/MK
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
de414.bsp Planetary ephemeris
pck00008.tpc Planet orientation and
radii
naif0008.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( '/kernels/gen/lsk/naif0008.tls'
'/kernels/gen/spk/de414.bsp'
'/kernels/gen/pck/pck00008.tpc'
)
Example:
Find the time during 2007 for which the subpoint position vector
of the sun on earth in the IAU_EARTH frame lies within a geodetic
latitude-longitude "box" defined as
16 degrees <= latitude <= 17 degrees
85 degrees <= longitude <= 86 degrees
This problem requires four searches, each search on one of the
box restrictions. The user needs also realize the temporal
behavior of latitude greatly differs from that of the longitude. The
sub-observer point latitude varies between approximately 23.44 degrees
and -23.44 degrees during the year. The sub-observer point longitude
varies between -180 degrees and 180 degrees in one day.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SpiceUsr.h"
#define MAXWIN 100
#define TIMFMT "YYYY-MON-DD HR:MN:SC.###### (TDB) ::TDB ::RND"
#define STRLEN 64
int main( int argc, char **argv )
{
/.
Create the needed windows. Note, one window
consists of two values, so the total number
of cell values to allocate equals twice
the number of intervals.
./
SPICEDOUBLE_CELL ( result1, 2*MAXWIN );
SPICEDOUBLE_CELL ( result2, 2*MAXWIN );
SPICEDOUBLE_CELL ( result3, 2*MAXWIN );
SPICEDOUBLE_CELL ( result4, 2*MAXWIN );
SPICEDOUBLE_CELL ( cnfine, 2 );
SpiceDouble begtim;
SpiceDouble endtim;
SpiceDouble step;
SpiceDouble adjust;
SpiceDouble refval;
SpiceDouble beg;
SpiceDouble end;
SpiceChar begstr [ STRLEN ];
SpiceChar endstr [ STRLEN ];
SpiceChar * target = "EARTH";
SpiceChar * obsrvr = "SUN";
SpiceChar * fixref = "IAU_EARTH";
SpiceChar * method = "Near point: ellipsoid";
SpiceChar * crdsys = "GEODETIC";
SpiceChar * abcorr = "NONE";
SpiceInt count;
SpiceInt i;
/.
Load kernels.
./
furnsh_c( "standard.tm" );
/.
Store the time bounds of our search interval in
the cnfine confinement window.
./
str2et_c( "2007 JAN 01", &begtim );
str2et_c( "2008 JAN 01", &endtim );
wninsd_c ( begtim, endtim, &cnfine );
/.
Perform four searches to determine the times when the
latitude-longitude box restriction conditions apply to
the subpoint vector.
Perform the searches such that the result window of a search
serves as the confinement window of the subsequent search.
Since the latitude coordinate varies slowly and is well behaved
over the time of the confinement window, search first for the
windows satisfying the latitude requirements, then use that result
as confinement for the longitude search.
./
/.
The latitude varies relatively slowly, ~46 degrees during the
year. The extrema occur approximately every six months.
Search using a step size less than half that value (180 days).
For this example use ninety days (in units of seconds).
./
step = (90.)*spd_c();
adjust = 0.;
{
SpiceChar * coord = "LATITUDE";
SpiceChar * relate = ">";
refval = 16. *rpd_c();
gfsubc_c ( target, fixref,
method, abcorr, obsrvr,
crdsys, coord,
relate, refval,
adjust, step,
MAXWIN,
&cnfine, &result1 );
}
{
SpiceChar * coord = "LATITUDE";
SpiceChar * relate = "<";
refval = 17. *rpd_c();
gfsubc_c ( target, fixref,
method, abcorr, obsrvr,
crdsys, coord,
relate, refval,
adjust, step,
MAXWIN,
&result1, &result2 );
}
/.
Now the longitude search.
./
/.
Reset the stepsize to something appropriate for the 360
degrees in 24 hours domain. The longitude shows near
linear behavior so use a stepsize less than half the period
of twelve hours. Ten hours will suffice in this case.
./
step = (10./24.)*spd_c();
{
SpiceChar * coord = "LONGITUDE";
SpiceChar * relate = ">";
refval = 85. *rpd_c();
gfsubc_c ( target, fixref,
method, abcorr, obsrvr,
crdsys, coord,
relate, refval,
adjust, step,
MAXWIN,
&result2, &result3 );
/.
Contract the endpoints of each window to account
for possible round-off error at the -180/180 degree branch.
A contraction value of a millisecond should eliminate
any round-off caused branch crossing.
./
wncond_c( 1e-3, 1e-3, &result3 );
}
{
SpiceChar * coord = "LONGITUDE";
SpiceChar * relate = "<";
refval = 86. *rpd_c();
gfsubc_c ( target, fixref,
method, abcorr, obsrvr,
crdsys, coord,
relate, refval,
adjust, step,
MAXWIN,
&result3, &result4 );
}
/.
List the beginning and ending points in each interval
if result contains data.
./
count = wncard_c( &result4 );
/.
Display the results.
./
if (count == 0 )
{
printf ( "Result window is empty.\n\n" );
}
else
{
for ( i = 0; i < count; i++ )
{
/.
Fetch the endpoints of the Ith interval
of the result window.
./
wnfetd_c ( &result4, i, &beg, &end );
timout_c ( beg, TIMFMT, STRLEN, begstr );
timout_c ( end, TIMFMT, STRLEN, endstr );
printf ( "Interval %d\n", i + 1);
printf ( "Beginning TDB %s \n", begstr );
printf ( "Ending TDB %s \n\n", endstr );
}
}
kclear_c();
return( 0 );
}
The program outputs:
Interval 1
Beginning TDB 2007-MAY-05 06:14:04.637735 (TDB)
Ending TDB 2007-MAY-05 06:18:04.621908 (TDB)
Interval 2
Beginning TDB 2007-MAY-06 06:13:59.583483 (TDB)
Ending TDB 2007-MAY-06 06:17:59.569239 (TDB)
Interval 3
Beginning TDB 2007-MAY-07 06:13:55.102939 (TDB)
Ending TDB 2007-MAY-07 06:17:55.090299 (TDB)
Interval 4
Beginning TDB 2007-MAY-08 06:13:51.202604 (TDB)
Ending TDB 2007-MAY-08 06:17:51.191583 (TDB)
Interval 5
Beginning TDB 2007-AUG-06 06:23:17.282927 (TDB)
Ending TDB 2007-AUG-06 06:27:17.264009 (TDB)
Interval 6
Beginning TDB 2007-AUG-07 06:23:10.545441 (TDB)
Ending TDB 2007-AUG-07 06:27:10.524926 (TDB)
Interval 7
Beginning TDB 2007-AUG-08 06:23:03.233996 (TDB)
Ending TDB 2007-AUG-08 06:27:03.211889 (TDB)
-Restrictions
1) The kernel files to be used by this routine must be loaded
(normally via the CSPICE routine furnsh_c) before this routine
is called.
2) This routine has the side effect of re-initializing the
coordinate quantity utility package. Callers may
need to re-initialize the package after calling this routine.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
E.D. Wright (JPL)
-Version
-CSPICE Version 1.0.1, 26-AUG-2009, EDW (JPL)
Edit to Example description, replaced "intercept" with
"sub-observer point."
Correction of several typos.
-CSPICE Version 1.0.0, 10-FEB-2009 (NJB) (EDW)
-Index_Entries
GF subpoint coordinate search
-&
*/
{ /* Begin gfsubc_c */
/*
Local variables
*/
doublereal * work;
SpiceInt nBytes;
static SpiceInt nw = SPICE_GF_NWMAX;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "gfsubc_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2 ( CHK_STANDARD, "gfsubc_c", SPICE_DP, cnfine, result );
/*
Initialize the input cells if necessary.
*/
CELLINIT2 ( cnfine, result );
/*
Check the input strings to make sure each pointer is non-null
and each string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "gfsubc_c", target );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", fixref );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", method );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", abcorr );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", obsrvr );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", crdsys );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", coord );
CHKFSTR ( CHK_STANDARD, "gfsubc_c", relate );
/*
Check the workspace size; some mallocs have a violent
dislike for negative allocation amounts. To be safe,
rule out a count of zero intervals as well.
*/
if ( nintvls < 1 )
{
setmsg_c ( "The specified workspace interval count # was "
"less than the minimum allowed value of one (1)." );
errint_c ( "#", nintvls );
sigerr_c ( "SPICE(VALUEOUTOFRANGE)" );
chkout_c ( "gfposc_c" );
return;
}
/*
Allocate the workspace. 'nintvls' indicates the maximum number of
intervals returned in 'result'. An interval consists of
two values.
*/
nintvls = 2 * nintvls;
nBytes = ( nintvls + SPICE_CELL_CTRLSZ ) * nw * sizeof(SpiceDouble);
work = (doublereal *) alloc_SpiceMemory( nBytes );
if ( !work )
{
setmsg_c ( "Workspace allocation of # bytes failed due to "
"malloc failure" );
errint_c ( "#", nBytes );
sigerr_c ( "SPICE(MALLOCFAILED)" );
chkout_c ( "gfsubc_c" );
return;
}
/*
Let the f2'd routine do the work.
*/
gfsubc_ ( ( char * ) target,
( char * ) fixref,
( char * ) method,
( char * ) abcorr,
( char * ) obsrvr,
( char * ) crdsys,
( char * ) coord,
( char * ) relate,
( doublereal * ) &refval,
( doublereal * ) &adjust,
( doublereal * ) &step,
( doublereal * ) (cnfine->base),
( integer * ) &nintvls,
( integer * ) &nw,
( doublereal * ) work,
( doublereal * ) (result->base),
( ftnlen ) strlen(target),
( ftnlen ) strlen(fixref),
( ftnlen ) strlen(method),
( ftnlen ) strlen(abcorr),
( ftnlen ) strlen(obsrvr),
( ftnlen ) strlen(crdsys),
( ftnlen ) strlen(coord),
( ftnlen ) strlen(relate) );
/*
De-allocate the workspace.
*/
free_SpiceMemory( work );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, result ) ;
}
ALLOC_CHECK;
chkout_c ( "gfsubc_c" );
} /* End gfsubc_c */
void gfposc_c ( ConstSpiceChar * target,
ConstSpiceChar * frame,
ConstSpiceChar * abcorr,
ConstSpiceChar * obsrvr,
ConstSpiceChar * crdsys,
ConstSpiceChar * coord,
ConstSpiceChar * relate,
SpiceDouble refval,
SpiceDouble adjust,
SpiceDouble step,
SpiceInt nintvls,
SpiceCell * cnfine,
SpiceCell * result )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
SPICE_GF_CNVTOL
P Convergence tolerance.
target I Name of the target body
frame I Name of the reference frame for coordinate calculations
abcorr I Aberration correction flag
obsrvr I Name of the observing body
crdsys I Name of the coordinate system containing COORD
coord I Name of the coordinate of interest
relate I Operator that either looks for an extreme value
(max, min, local, absolute) or compares the
coordinate value and refval
refval I Reference value
adjust I Adjustment value for absolute extrema searches
step I Step size used for locating extrema and roots
nintvls I Workspace window interval count
cnfine I-O SPICE window to which the search is restricted
result O SPICE window containing results
-Detailed_Input
target the string name of a target body. Optionally, you may
supply the integer ID code for the object as an
integer string. For example both 'MOON' and '301'
are legitimate strings that indicate the moon is the
target body.
The target and observer define a position vector
that points from the observer to the target.
frame the string name of the reference frame in which to perform
state look-ups and coordinate calculations.
The SPICE frame subsystem must recognize the 'frame' name.
abcorr the string description of the aberration corrections to apply
to the state evaluations to account for one-way light time
and stellar aberration.
This routine accepts the same aberration corrections as does
the SPICE routine SPKEZR. See the header of SPKEZR for a
detailed description of the aberration correction options.
For convenience, the options are listed below:
'NONE' Apply no correction.
'LT' "Reception" case: correct for
one-way light time using a Newtonian
formulation.
'LT+S' "Reception" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
'CN' "Reception" case: converged
Newtonian light time correction.
'CN+S' "Reception" case: converged
Newtonian light time and stellar
aberration corrections.
'XLT' "Transmission" case: correct for
one-way light time using a Newtonian
formulation.
'XLT+S' "Transmission" case: correct for
one-way light time and stellar
aberration using a Newtonian
formulation.
'XCN' "Transmission" case: converged
Newtonian light time correction.
'XCN+S' "Transmission" case: converged
Newtonian light time and stellar
aberration corrections.
The abcorr string lacks sensitivity to case, and to embedded,
leading and trailing blanks.
obsrvr the string naming the observing body. Optionally, you
may supply the ID code of the object as an integer
string. For example, both 'EARTH' and '399' are
legitimate strings to supply to indicate the
observer is Earth.
crdsys the string name of the coordinate system for which the
coordinate of interest is a member.
coord the string name of the coordinate of interest in crdsys.
The supported coordinate systems and coordinate names are:
Coordinate System (CRDSYS) Coordinates (COORD) Range
'RECTANGULAR' 'X'
'Y'
'Z'
'LATITUDINAL' 'RADIUS'
'LONGITUDE' (-Pi,Pi]
'LATITUDE' [-Pi/2,Pi/2]
'RA/DEC' 'RANGE'
'RIGHT ASCENSION' [0,2Pi)
'DECLINATION' [-Pi/2,Pi/2]
'SPHERICAL' 'RADIUS'
'COLATITUDE' [0,Pi]
'LONGITUDE' (-Pi,Pi]
'CYLINDRICAL' 'RADIUS'
'LONGITUDE' [0,2Pi)
'Z'
'GEODETIC' 'LONGITUDE' (-Pi,Pi]
'LATITUDE' [-Pi/2,Pi/2]
'ALTITUDE'
'PLANETOGRAPHIC' 'LONGITUDE' [0,2Pi)
'LATITUDE' [-Pi/2,Pi/2]
'ALTITUDE'
Limit searches for coordinate events in the GEODETIC and
PLANETOGRAPHIC coordinate systems to TARGET bodies with
axial symmetry in the equatorial plane, i.e. equality
of the body X and Y radii (oblate or prolate spheroids).
relate the string or character describing the relational operator
used to define a constraint on the selected coordinate of the
observer-target vector. The result window found by this routine
indicates the time intervals where the constraint is satisfied.
Supported values of relate and corresponding meanings are
shown below:
'>' Separation is greater than the reference
value refval.
'=' Separation is equal to the reference
value refval.
'<' Separation is less than the reference
value refval.
'ABSMAX' Separation is at an absolute maximum.
'ABSMIN' Separation is at an absolute minimum.
'LOCMAX' Separation is at a local maximum.
'LOCMIN' Separation is at a local minimum.
The caller may indicate that the region of interest
is the set of time intervals where the quantity is
within a specified measure of an absolute extremum.
The argument ADJUST (described below) is used to
specify this measure.
Local extrema are considered to exist only in the
interiors of the intervals comprising the confinement
window: a local extremum cannot exist at a boundary
point of the confinement window.
The relate string lacks sensitivity to case, leading
and trailing blanks.
refval the double precision reference value used together with
relate argument to define an equality or inequality to
satisfy by the selected coordinate of the observer-target
vector. See the discussion of relate above for
further information.
The units of refval correspond to the type as defined
by coord, radians for angular measures, kilometers for
distance measures.
adjust a double precision value used to modify searches for
absolute extrema: when relate is set to ABSMAX or ABSMIN and
adjust is set to a positive value, gfposc_c finds times when the
observer-target vector coordinate is within adjust
radians/kilometers of the specified extreme value.
For relate set to ABSMAX, the result window contains
time intervals when the observer-target vector coordinate has
values between ABSMAX - adjust and ABSMAX.
For relate set to ABSMIN, the result window contains
time intervals when the observer-target vector coordinate has
values between ABSMIN and ABSMIN + adjust.
adjust is not used for searches for local extrema,
equality or inequality conditions.
step the double precision time step size to use in the search.
step must be short enough for a search using this step
size to locate the time intervals where coordinate function
of the observer-target vector is monotone increasing or
decreasing. However, step must not be *too* short, or
the search will take an unreasonable amount of time.
The choice of step affects the completeness but not
the precision of solutions found by this routine; the
precision is controlled by the convergence tolerance.
step has units of seconds.
nintvls an integer value specifying the number of intervals in the
the internal workspace array used by this routine. 'nintvls'
should be at least as large as the number of intervals
within the search region on which the specified observer-target
vector coordinate function is monotone increasing or decreasing.
It does no harm to pick a value of 'nintvls' larger than the
minimum required to execute the specified search, but if chosen
too small, the search will fail.
cnfine a double precision SPICE window that confines the time
period over which the specified search is conducted.
cnfine may consist of a single interval or a collection
of intervals.
In some cases the confinement window can be used to
greatly reduce the time period that must be searched
for the desired solution. See the Particulars section
below for further discussion.
See the Examples section below for a code example
that shows how to create a confinement window.
-Detailed_Output
cnfine is the input confinement window, updated if necessary
so the control area of its data array indicates the
window's size and cardinality. The window data are
unchanged.
result the SPICE window of intervals, contained within the
confinement window cnfine, on which the specified
constraint is satisfied.
If result is non-empty on input, its contents
will be discarded before gfposc_c conducts its
search.
result must be declared and initialized with sufficient
size to capture the full set of time intervals
within the search region on which the specified constraint
is satisfied.
If the search is for local extrema, or for absolute
extrema with adjust set to zero, then normally each
interval of result will be a singleton: the left and
right endpoints of each interval will be identical.
If no times within the confinement window satisfy the
constraint, result will be returned with a
cardinality of zero.
-Parameters
SPICE_GF_CNVTOL
is the convergence tolerance used for finding endpoints
of the intervals comprising the result window.
SPICE_GF_CNVTOL is used to determine when binary searches
for roots should terminate: when a root is bracketed
within an interval of length SPICE_GF_CNVTOL; the root is
considered to have been found.
The accuracy, as opposed to precision, of roots found by
this routine depends on the accuracy of the input data.
In most cases, the accuracy of solutions will be inferior
to their precision.
SPICE_GF_CNVTOL has the value 1.0e-6. Units are TDB
seconds.
-Exceptions
1) In order for this routine to produce correct results,
the step size must be appropriate for the problem at hand.
Step sizes that are too large may cause this routine to miss
roots; step sizes that are too small may cause this routine
to run unacceptably slowly and in some cases, find spurious
roots.
This routine does not diagnose invalid step sizes, except
that if the step size is non-positive, an error is signaled
by a routine in the call tree of this routine.
2) Due to numerical errors, in particular,
- Truncation error in time values
- Finite tolerance value
- Errors in computed geometric quantities
it is *normal* for the condition of interest to not always be
satisfied near the endpoints of the intervals comprising the
result window.
The result window may need to be contracted slightly by the
caller to achieve desired results. The SPICE window routine
wncond_c can be used to contract the result window.
3) If an error (typically cell overflow) occurs while performing
window arithmetic, the error will be diagnosed by a routine
in the call tree of this routine.
4) If the relational operator `relate' is not recognized, an
error is signaled by a routine in the call tree of this
routine.
5) If the aberration correction specifier contains an
unrecognized value, an error is signaled by a routine in the
call tree of this routine.
6) If `adjust' is negative, an error is signaled by a routine in
the call tree of this routine.
7) If either of the input body names do not map to NAIF ID
codes, an error is signaled by a routine in the call tree of
this routine.
8) If required ephemerides or other kernel data are not
available, an error is signaled by a routine in the call tree
of this routine.
9) If any input string argument pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
10) If any input string argument is empty, the error
SPICE(EMPTYSTRING) will be signaled.
11) If the workspace interval count 'nintvls' is less than 1, the
error SPICE(VALUEOUTOFRANGE) will be signaled.
12) If the required amount of workspace memory cannot be
allocated, the error SPICE(MALLOCFAILURE) will be
signaled.
-Files
Appropriate SPK and PCK kernels must be loaded by the
calling program before this routine is called.
The following data are required:
- SPK data: the calling application must load ephemeris data
for the targets, observer, and any intermediate objects in
a chain connecting the targets and observer that cover the time
period specified by the window CNFINE. If aberration
corrections are used, the states of target and observer
relative to the solar system barycenter must be calculable
from the available ephemeris data. Typically ephemeris data
are made available by loading one or more SPK files using
FURNSH.
- PCK data: bodies modeled as triaxial ellipsoids must have
semi-axis lengths provided by variables in the kernel pool.
Typically these data are made available by loading a text
PCK file using FURNSH.
- If non-inertial reference frames are used, then PCK
files, frame kernels, C-kernels, and SCLK kernels may be
needed.
Such kernel data are normally loaded once per program
run, NOT every time this routine is called.
-Particulars
This routine provides a simpler, but less flexible interface
than does the routine gfevnt_c for conducting searches for
observer-target vector coordinate value events. Applications
that require support for progress reporting, interrupt
handling, non-default step or refinement functions, or non-default
convergence tolerance should call gfevnt_c rather than this routine.
This routine determines a set of one or more time intervals
within the confinement window when the selected coordinate of
the observer-target vector satisfies a caller-specified
constraint. The resulting set of intervals is returned as a SPICE
window.
Below we discuss in greater detail aspects of this routine's
solution process that are relevant to correct and efficient
use of this routine in user applications.
The Search Process
==================
Regardless of the type of constraint selected by the caller, this
routine starts the search for solutions by determining the time
periods, within the confinement window, over which the specified
coordinate function is monotone increasing and monotone
decreasing. Each of these time periods is represented by a SPICE
window. Having found these windows, all of the coordinate
function's local extrema within the confinement window are known.
Absolute extrema then can be found very easily.
Within any interval of these "monotone" windows, there will be at
most one solution of any equality constraint. Since the boundary
of the solution set for any inequality constraint is the set
of points where an equality constraint is met, the solutions of
both equality and inequality constraints can be found easily
once the monotone windows have been found.
Step Size
=========
The monotone windows (described above) are found using a two-step
search process. Each interval of the confinement window is
searched as follows: first, the input step size is used to
determine the time separation at which the sign of the rate of
change of coordinate will be sampled. Starting at
the left endpoint of an interval, samples will be taken at each
step. If a change of sign is found, a root has been bracketed; at
that point, the time at which the time derivative of the coordinate
is zero can be found by a refinement process, for example,
using a binary search.
Note that the optimal choice of step size depends on the lengths
of the intervals over which the coordinate function is monotone:
the step size should be shorter than the shortest of these
intervals (within the confinement window).
The optimal step size is *not* necessarily related to the lengths
of the intervals comprising the result window. For example, if
the shortest monotone interval has length 10 days, and if the
shortest result window interval has length 5 minutes, a step size
of 9.9 days is still adequate to find all of the intervals in the
result window. In situations like this, the technique of using
monotone windows yields a dramatic efficiency improvement over a
state-based search that simply tests at each step whether the
specified constraint is satisfied. The latter type of search can
miss solution intervals if the step size is shorter than the
shortest solution interval.
Having some knowledge of the relative geometry of the target and
observer can be a valuable aid in picking a reasonable step size.
In general, the user can compensate for lack of such knowledge by
picking a very short step size; the cost is increased computation
time.
Note that the step size is not related to the precision with which
the endpoints of the intervals of the result window are computed.
That precision level is controlled by the convergence tolerance.
Convergence Tolerance
=====================
As described above, the root-finding process used by this routine
involves first bracketing roots and then using a search process
to locate them. "Roots" are both times when local extrema are
attained and times when the distance function is equal to a
reference value. All endpoints of the intervals comprising the
result window are either endpoints of intervals of the
confinement window or roots.
Once a root has been bracketed, a refinement process is used to
narrow down the time interval within which the root must lie.
This refinement process terminates when the location of the root
has been determined to within an error margin called the
"convergence tolerance." The convergence tolerance used by this
routine is set by the parameter SPICE_GF_CNVTOL.
The value of SPICE_GF_CNVTOL is set to a "tight" value in the f2c'd
routine so that the tolerance doesn't become the limiting factor
in the accuracy of solutions found by this routine. In general the
accuracy of input data will be the limiting factor.
To use a different tolerance value, a lower-level GF routine such
as gfevnt_c must be called. Making the tolerance tighter than
SPICE_GF_CNVTOL is unlikely to be useful, since the results are unlikely
to be more accurate. Making the tolerance looser will speed up
searches somewhat, since a few convergence steps will be omitted.
However, in most cases, the step size is likely to have a much
greater effect on processing time than would the convergence
tolerance.
The Confinement Window
======================
The simplest use of the confinement window is to specify a time
interval within which a solution is sought. However, the
confinement window can, in some cases, be used to make searches
more efficient. Sometimes it's possible to do an efficient search
to reduce the size of the time period over which a relatively
slow search of interest must be performed.
Practical use of the coordinate search capability would likely
consist of searches over multiple coordinate constraints to find
time intervals that satisfies the constraints. An effective
technique to accomplish such a search is to use the result
window from one search as the confinement window of the next.
Longitude and Right Ascension
=============================
The cyclic nature of the longitude and right ascension coordinates
produces branch cuts at +/- 180 degrees longitude and 0-360
longitude. Round-off error may cause solutions near these branches
to cross the branch. Use of the SPICE routine wncond_c will contract
solution windows by some epsilon, reducing the measure of the
windows and eliminating the branch crossing. A one millisecond
contraction will in most cases eliminate numerical round-off caused
branch crossings.
-Examples
The numerical results shown for these examples may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
The examples shown below require a "standard" set of SPICE
kernels. We list these kernels in a meta kernel named 'standard.tm'.
KPL/MK
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
de414.bsp Planetary ephemeris
pck00008.tpc Planet orientation and radii
naif0009.tls Leapseconds kernel
earthstns_itrf93_050714.bsp SPK for DSN Station Locations
earth_topo_050714.tf Topocentric DSN stations frame
definitions
earth_000101_080120_071029.bpc High precision earth PCK
\begindata
KERNELS_TO_LOAD = (
'/kernels/gen/lsk/naif0008.tls'
'/kernels/gen/spk/de414.bsp'
'/kernels/gen/pck/pck00008.tpc'
'/kernels/gen/spk/earthstns_itrf93_050714.bsp',
'/kernels/gen/fk/earth_topo_050714.tf',
'/kernels/gen/pck/earth_000101_080120_071029.bpc',
)
Example(1):
Find the time during 2007 for which the latitude of the
Earth-Sun vector in IAU_EARTH frame has the maximum value,
i.e. the latitude of the Tropic of Cancer.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SpiceUsr.h"
#define MAXWIN 750
#define TIMFMT "YYYY-MON-DD HR:MN:SC.###### (TDB) ::TDB ::RND"
#define TIMLEN 41
int main( int argc, char **argv )
{
/.
Create the needed windows. Note, one window
consists of two values, so the total number
of cell values to allocate is twice
the number of intervals.
./
SPICEDOUBLE_CELL ( result, 2*MAXWIN );
SPICEDOUBLE_CELL ( cnfine, 2 );
SpiceDouble begtim;
SpiceDouble endtim;
SpiceDouble step;
SpiceDouble adjust;
SpiceDouble refval;
SpiceDouble beg;
SpiceDouble end;
SpiceChar begstr [ TIMLEN ];
SpiceChar endstr [ TIMLEN ];
SpiceChar * relate = "ABSMAX";
SpiceChar * crdsys = "LATITUDINAL";
SpiceChar * coord = "LATITUDE";
SpiceChar * targ = "SUN";
SpiceChar * obsrvr = "EARTH";
SpiceChar * frame = "IAU_EARTH";
SpiceChar * abcorr = "NONE";
SpiceInt count;
SpiceInt i;
/.
Load kernels.
./
furnsh_c( "standard.tm" );
/.
Store the time bounds of our search interval in
the cnfine confinement window.
./
str2et_c( "2007 JAN 01", &begtim );
str2et_c( "2008 JAN 01", &endtim );
wninsd_c ( begtim, endtim, &cnfine );
/.
The latitude varies relatively slowly, ~46 degrees during the
year. The extrema occur approximately every six months.
Search using a step size less than half that value (180 days).
For this example use ninety days (in units of seconds).
./
step = (90.)*spd_c();
adjust = 0.;
refval = 0;
/.
List the beginning and ending points in each interval
if result contains data.
./
gfposc_c ( targ,
frame,
abcorr,
obsrvr,
crdsys,
coord,
relate,
refval,
adjust,
step,
MAXWIN,
&cnfine,
&result );
count = wncard_c( &result );
/.
Display the results.
./
if (count == 0 )
{
printf ( "Result window is empty.\n\n" );
}
else
{
for ( i = 0; i < count; i++ )
{
/.
Fetch the endpoints of the Ith interval
of the result window.
./
wnfetd_c ( &result, i, &beg, &end );
if ( beg == end )
{
timout_c ( beg, TIMFMT, TIMLEN, begstr );
printf ( "Event time: %s\n", begstr );
}
else
{
timout_c ( beg, TIMFMT, TIMLEN, begstr );
timout_c ( end, TIMFMT, TIMLEN, endstr );
printf ( "Interval %d\n", i + 1);
printf ( "From : %s \n", begstr );
printf ( "To : %s \n", endstr );
printf( " \n" );
}
}
}
kclear_c();
return( 0 );
}
The program outputs:
Event time: 2007-JUN-21 17:54:13.166910 (TDB)
Example(2):
A minor modification of the program listed in Example 1; find the
time during 2007 for which the latitude of the Earth-Sun vector
in IAU_EARTH frame has the minimum value, i.e. the latitude of
the Tropic of Capricorn.
Edit the example program, assign:
SpiceChar * relate = "ABSMIN";
The program outputs:
Event time: 2007-DEC-22 06:04:32.630160 (TDB)
Example(3):
Find the time during 2007 for which the Z component of the
Earth-Sun vector in IAU_EARTH frame has value 0, i.e. crosses
the equatorial plane (this also defines a zero latitude).
The search should return two times, one for an ascending
passage and one for descending.
Edit the example program, assign:
SpiceChar * relate = "=";
SpiceChar * crdsys = "RECTANGULAR";
SpiceChar * coord = "Z";
Note, this RELATE operator refers to the REFVAL value,
assigned to 0.D0 for this example.
The program outputs:
Event time: 2007-MAR-21 00:01:25.495120 (TDB)
Event time: 2007-SEP-23 09:46:39.574124 (TDB)
Example(4):
Find the times between Jan 1, 2007 and Jan 1, 2008 corresponding
to the apoapsis on the Moon's orbit around the Earth (note, the
GFDIST routine can also perform this search).
Edit the example program, assign:
This search requires a change in the step size since the Moon's
orbit about the earth (earth-moon barycenter) has a twenty-eight
day period. Use a step size something less than half that value.
In this case, we use twelve days.
SpiceChar * relate = "LOCMAX";
SpiceChar * crdsys = "SPHERICAL";
SpiceChar * coord = "RADIUS";
SpiceChar * targ = "MOON";
SpiceChar * frame = "J2000";
step = 12.*spd_c();
The program outputs:
Event time: 2007-JAN-10 16:26:18.805837 (TDB)
Event time: 2007-FEB-07 12:39:35.078525 (TDB)
Event time: 2007-MAR-07 03:38:07.334769 (TDB)
Event time: 2007-APR-03 08:38:55.222606 (TDB)
Event time: 2007-APR-30 10:56:49.847027 (TDB)
Event time: 2007-MAY-27 22:03:28.857783 (TDB)
Event time: 2007-JUN-24 14:26:23.639351 (TDB)
Event time: 2007-JUL-22 08:43:50.135565 (TDB)
Event time: 2007-AUG-19 03:28:33.538169 (TDB)
Event time: 2007-SEP-15 21:07:13.964698 (TDB)
Event time: 2007-OCT-13 09:52:30.819372 (TDB)
Event time: 2007-NOV-09 12:32:50.070555 (TDB)
Event time: 2007-DEC-06 16:54:31.225504 (TDB)
Example(5):
Find times between Jan 1, 2007 and Jan 1, 2008 when the latitude
(elevation) of the observer-target vector between DSS 17 and the
Moon, as observed in the DSS 17 topocentric (station) frame,
exceeds 83 degrees.
Edit the example program, assign:
This search uses a step size of four hours since the time
for all declination zero-to-max-to-zero passes within
the search window exceeds eight hours.
SpiceChar * relate = ">";
SpiceChar * crdsys = "LATITUDINAL";
SpiceChar * coord = "LATITUDE";
SpiceChar * targ = "MOON";
SpiceChar * obsrvr = "DSS-17";
SpiceChar * frame = "DSS-17_TOPO";
step = (4./24.)*spd_c();
refval = 83. * rpd_c();
The program outputs:
Interval 1
From : 2007-FEB-26 03:18:48.229806 (TDB)
To : 2007-FEB-26 03:31:29.734169 (TDB)
Interval 2
From : 2007-MAR-25 01:12:38.551183 (TDB)
To : 2007-MAR-25 01:23:53.908601 (TDB)
-Restrictions
1) The kernel files to be used by this routine must be loaded
(normally via the CSPICE routine furnsh_c) before this routine
is called.
2) This routine has the side effect of re-initializing the
coordinate quantity utility package. Callers may
need to re-initialize the package after calling this routine.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
E.D. Wright (JPL)
-Version
-CSPICE Version 1.0.1, 26-AUG-2009 (EDW)
Correction of several typos.
-CSPICE Version 1.0.0, 10-FEB-2009 (NJB) (EDW)
-Index_Entries
GF position coordinate search
-&
*/
{ /* Begin gfposc_c */
/*
Local variables
*/
doublereal * work;
SpiceInt nBytes;
static SpiceInt nw = SPICE_GF_NWMAX;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "gfposc_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2 ( CHK_STANDARD, "gfposc_c", SPICE_DP, cnfine, result );
/*
Initialize the input cells if necessary.
*/
CELLINIT2 ( cnfine, result );
/*
Check the input strings to make sure each pointer is non-null
and each string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "gfposc_c", target );
CHKFSTR ( CHK_STANDARD, "gfposc_c", frame );
CHKFSTR ( CHK_STANDARD, "gfposc_c", abcorr );
CHKFSTR ( CHK_STANDARD, "gfposc_c", obsrvr );
CHKFSTR ( CHK_STANDARD, "gfposc_c", crdsys );
CHKFSTR ( CHK_STANDARD, "gfposc_c", coord );
CHKFSTR ( CHK_STANDARD, "gfposc_c", relate );
/*
Check the workspace size; some mallocs have a violent
dislike for negative allocation amounts. To be safe,
rule out a count of zero intervals as well.
*/
if ( nintvls < 1 )
{
setmsg_c ( "The specified workspace interval count # was "
"less than the minimum allowed value of one (1)." );
errint_c ( "#", nintvls );
sigerr_c ( "SPICE(VALUEOUTOFRANGE)" );
chkout_c ( "gfposc_c" );
return;
}
/*
Allocate the workspace. 'nintvls' indicates the maximum number of
intervals returned in 'result'. An interval consists of
two values.
*/
nintvls = 2 * nintvls;
nBytes = ( nintvls + SPICE_CELL_CTRLSZ ) * nw * sizeof(SpiceDouble);
work = (doublereal *) alloc_SpiceMemory( nBytes );
if ( !work )
{
setmsg_c ( "Workspace allocation of # bytes failed due to "
"malloc failure" );
errint_c ( "#", nBytes );
sigerr_c ( "SPICE(MALLOCFAILED)" );
chkout_c ( "gfposc_c" );
return;
}
/*
Let the f2'd routine do the work.
*/
gfposc_( ( char * ) target,
( char * ) frame,
( char * ) abcorr,
( char * ) obsrvr,
( char * ) crdsys,
( char * ) coord,
( char * ) relate,
( doublereal * ) &refval,
( doublereal * ) &adjust,
( doublereal * ) &step,
( doublereal * ) (cnfine->base),
( integer * ) &nintvls,
( integer * ) &nw,
( doublereal * ) work,
( doublereal * ) (result->base),
( ftnlen ) strlen(target),
( ftnlen ) strlen(frame),
( ftnlen ) strlen(abcorr),
( ftnlen ) strlen(obsrvr),
( ftnlen ) strlen(crdsys),
( ftnlen ) strlen(coord),
( ftnlen ) strlen(relate) );
/*
De-allocate the workspace.
*/
free_SpiceMemory( work );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, result ) ;
}
ALLOC_CHECK;
chkout_c ( "gfposc_c" );
} /* End gfposc_c */
void ekbseg_c ( SpiceInt handle,
ConstSpiceChar * tabnam,
SpiceInt ncols,
SpiceInt cnmlen,
const void * cnames,
SpiceInt declen,
const void * decls,
SpiceInt * segno )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
handle I File handle.
tabnam I Table name.
ncols I Number of columns in the segment.
cnmlen I Length of names in in column name array.
cnames I Names of columns.
declen I Length of declaration strings in declaration array.
decls I Declarations of columns.
segno O Segment number.
-Detailed_Input
handle the handle of an EK file that is open for writing.
tabnam is the name of the EK table to which the current
segment belongs. All segments in the EK file
designated by handle must have identical column
attributes. tabnam must not exceed SPICE_EK_TNAMSZ
characters (see SpiceEK.h) in length. Case is not
significant. Table names must start with a letter and
contain only characters from the set
{A-Z,a-z,0-9,$,_}.
ncols is the number of columns in a new segment.
cnmlen,
cnames are, respectively, the length of the column name
strings in the column name array, and the base
address of the array itself. The array should have
dimensions
[ncols][cnmlen]
declen,
decls are, respectively, the length of the declaration
strings in the declaration array, and the base
address of the array itself. The array should have
dimensions
[ncols][declen]
The Ith element of cnames and the Ith element of decls
apply to the Ith column in the segment.
Column names must not exceed CSPICE_EK_CNAMSZ
characters (see SpiceEK.h) in length. Case is not
significant. Column names must start with a letter
and contain only characters from the set
{A-Z,a-z,0-9,$,_}.
The declarations are strings that contain
"keyword=value" assignments that define the
attributes of the columns to which they apply. The
column attributes that are defined by a column
declaration are:
DATATYPE
SIZE
<is the column indexed?>
<does the column allow null values?>
The form of a declaration is
"DATATYPE = <type>,
SIZE = <size>,
INDEXED = <boolean>,
NULLS_OK = <boolean>"
For example, an indexed, scalar, integer column
that allows null values would have the declaration
"DATATYPE = INTEGER,
SIZE = 1,
INDEXED = TRUE,
NULLS_OK = TRUE"
Commas are required to separate the assignments
within declarations; white space is optional;
case is not significant.
The order in which the attribute keywords are
listed in declaration is not significant.
Every column in a segment must be declared.
Each column entry is effectively an array, each
element of which has the declared data type. The
SIZE keyword indicates how many elements are in
each entry of the column in whose declaration the
keyword appears. Note that only scalar-valued
columns (those for which SIZE = 1) may be
referenced in query constraints. A size
assignment has the syntax
SIZE = <integer>
or
SIZE = VARIABLE
The size value defaults to 1 if omitted.
The DATATYPE keyword defines the data type of
column entries. The DATATYPE assignment syntax
has any of the forms
DATATYPE = CHARACTER*(<length>)
DATATYPE = CHARACTER*(*)
DATATYPE = DOUBLE PRECISION
DATATYPE = INTEGER
DATATYPE = TIME
As the datatype declaration syntax suggests,
character strings may have fixed or variable
length. Variable-length strings are allowed only
in columns of size 1.
Optionally, scalar-valued columns may be indexed.
To create an index for a column, use the assignment
INDEXED = TRUE
By default, columns are not indexed.
Optionally, any column can allow null values. To
indicate that a column may allow null values, use
the assigment
NULLS_OK = TRUE
in the column declaration. By default, null
values are not allowed in column entries.
-Detailed_Output
segno is the number of the segment to which data is to be
added. Segments are numbered from 0 to nseg-1, where
nseg is the count of segments in the file. Segment
numbers are used as unique identifiers by other EK
access routines.
-Parameters
None.
-Exceptions
1) If handle is invalid, the error will be diagnosed by routines
called by this routine.
2) If tabnam is more than SPICE_EK_TNAMSZ characters long, the
error is diagnosed by routines called by this routine.
3) If tabnam contains any nonprintable characters, the error
is diagnosed by routines called by this routine.
4) If ncols is non-positive or greater than the maximum allowed
number SPICE_EK_MXCLSG, the error SPICE(INVALIDCOUNT) is
signaled.
5) If any column name exceeds SPICE_EK_CNAMSZ characters in
length, the error is diagnosed by routines called by this
routine.
6) If any column name contains non-printable characters, the
error is diagnosed by routines called by this routine.
7) If a declaration cannot be understood by this routine, the
error is diagnosed by routines called by this routine.
8) If an non-positive string length or element size is specified,
the error is diagnosed by routines called by this routine.
9) If an I/O error occurs while reading or writing the indicated
file, the error will be diagnosed by routines called by this
routine.
10) If the input string pointer for the table name is null, the
error SPICE(NULLPOINTER) will be signaled.
12) If the input tablen name string has length zero, the error
SPICE(EMPTYSTRING) will be signaled.
13) If the string pointer for cnames is null, the error
SPICE(NULLPOINTER) will be signaled.
14) If the string length cnmlen is less than 2, the error
SPICE(STRINGTOOSHORT) will be signaled.
15) If the string pointer for decls is null, the error
SPICE(NULLPOINTER) will be signaled.
16) If the string length declen is less than 2, the error
SPICE(STRINGTOOSHORT) will be signaled.
-Files
See the EK Required Reading for a discussion of the EK file
format.
-Particulars
This routine operates by side effects: it prepares an EK for
the addition of a new segment. It is not necessary to take
any special action to `complete' a segment; segments are readable
after the completion of any record insertion, deletion, write,
or update operation.
-Examples
1) Suppose we have an E-kernel named ORDER_DB.EK which contains
records of orders for data products. The E-kernel has a
table called DATAORDERS that consists of the set of columns
listed below:
DATAORDERS
Column Name Data Type
----------- ---------
ORDER_ID INTEGER
CUSTOMER_ID INTEGER
LAST_NAME CHARACTER*(*)
FIRST_NAME CHARACTER*(*)
ORDER_DATE TIME
COST DOUBLE PRECISION
The order database also has a table of items that have been
ordered. The columns of this table are shown below:
DATAITEMS
Column Name Data Type
----------- ---------
ITEM_ID INTEGER
ORDER_ID INTEGER
ITEM_NAME CHARACTER*(*)
DESCRIPTION CHARACTER*(*)
PRICE DOUBLE PRECISION
We'll suppose that the file ORDER_DB.EK contains two segments,
the first containing the DATAORDERS table and the second
containing the DATAITEMS table.
Below, we show how we'd open a new EK file and start the
first of the segments described above.
#include "SpiceUsr.h"
#include <stdio.h>
void main()
{
/.
Constants
./
#define CNMLEN SPICE_EK_CSTRLN
#define DECLEN 201
#define EKNAME "order_db.ek"
#define FNMLEN 50
#define IFNAME "Test EK/Created 20-SEP-1995"
#define LNMLEN 50
#define LSK "leapseconds.ker"
#define NCOLS 6
#define NRESVC 0
#define TABLE "DATAORDERS"
#define TNMLEN CSPICE_EK_TAB_NAM_LEN
#define UTCLEN 30
/.
Local variables
./
SpiceBoolean nlflgs [ NROWS ];
SpiceChar cdecls [ NCOLS ] [ DECLEN ];
SpiceChar cnames [ NCOLS ] [ CNMLEN ];
SpiceChar fnames [ NROWS ] [ FNMLEN ];
SpiceChar lnames [ NROWS ] [ LNMLEN ];
SpiceChar dateStr [ UTCLEN ];
SpiceDouble costs [ NROWS ];
SpiceDouble ets [ NROWS ];
SpiceInt cstids [ NROWS ];
SpiceInt ordids [ NROWS ];
SpiceInt handle;
SpiceInt i;
SpiceInt segno;
SpiceInt sizes [ NROWS ];
/.
Load a leapseconds kernel for UTC/ET conversion.
./
furnsh_c ( LSK );
/.
Open a new EK file. For simplicity, we will not
reserve any space for the comment area, so the
number of reserved comment characters is zero.
The constant IFNAME is the internal file name.
./
ekopn_c ( EKNAME, IFNAME, NRESVC, &handle );
/.
Set up the table and column names and declarations
for the DATAORDERS segment. We'll index all of
the columns. All columns are scalar, so we omit
the size declaration. Only the COST column may take
null values.
./
strcpy ( cnames[0], "ORDER_ID" );
strcpy ( cdecls[0], "DATATYPE = INTEGER, INDEXED = TRUE" );
strcpy ( cnames[1], "CUSTOMER_ID" );
strcpy ( cdecls[1], "DATATYPE = INTEGER, INDEXED = TRUE" );
strcpy ( cnames[2], "LAST_NAME" );
strcpy ( cdecls[2], "DATATYPE = CHARACTER*(*),"
"INDEXED = TRUE" );
strcpy ( cnames[3], "FIRST_NAME" );
strcpy ( cdecls[3], "DATATYPE = CHARACTER*(*),"
"INDEXED = TRUE" );
strcpy ( cnames[4], "ORDER_DATE" );
strcpy ( cdecls[4], "DATATYPE = TIME, INDEXED = TRUE" );
strcpy ( cnames[5], "COST" );
strcpy ( cdecls[5], "DATATYPE = DOUBLE PRECISION,"
"INDEXED = TRUE,"
"NULLS_OK = TRUE" );
/.
Start the segment.
./
ekbseg_c ( handle, TABLE, NCOLS, CNMLEN,
cnames, DECLEN, cdecls, &segno );
/.
Add data to the segment. No special action
is required to finish the segment.
./
[Data are added via calls to ekappr_c and the
ekacec_c, ekaced_c, and ekacei_c routines. See any
of these routines for examples.]
/.
At this point, the second segment could be
created by an analogous process. In fact, the
second segment could be created at any time; it is
not necessary to populate the first segment with
data before starting the second segment.
./
/.
The file must be closed by a call to ekcls_c.
./
ekcls_c ( handle );
}
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.1.0, 12-JUL-2002 (NJB)
Call to C2F_CreateStrArr_Sig replaced with call to C2F_MapStrArr.
-CSPICE Version 1.0.0, 17-NOV-2001 (NJB)
-Index_Entries
start new E-kernel segment
start new EK segment
-&
*/
{ /* Begin ekbseg_c */
/*
Local variables
*/
SpiceChar * fCnameArr;
SpiceChar * fCdeclArr;
SpiceInt fCnameLen;
SpiceInt fCdeclLen;
/*
Participate in error tracing.
*/
chkin_c ( "ekbseg_c" );
/*
Check the table name to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "ekbseg_c", tabnam );
/*
Check the column name array to make sure the pointer is non-null
and the string length is non-zero. Note: this check is normally
done for output strings: CHKOSTR is the macro that does the job.
*/
CHKOSTR ( CHK_STANDARD, "ekbseg_c", cnames, cnmlen );
/*
Check the declaration array to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKOSTR ( CHK_STANDARD, "ekbseg_c", decls, declen );
C2F_MapStrArr ( "ekbseg_c",
ncols, cnmlen, cnames, &fCnameLen, &fCnameArr );
if ( failed_c() )
{
chkout_c ( "ekbseg_c" );
return;
}
C2F_MapStrArr ( "ekbseg_c",
ncols, declen, decls, &fCdeclLen, &fCdeclArr );
if ( failed_c() )
{
free ( fCnameArr );
chkout_c ( "ekbseg_c" );
return;
}
/*
Call the f2c'd Fortran routine. Use explicit type casts for every
type defined by f2c.
*/
ekbseg_ ( ( integer * ) &handle,
( char * ) tabnam,
( integer * ) &ncols,
( char * ) fCnameArr,
( char * ) fCdeclArr,
( integer * ) segno,
( ftnlen ) strlen(tabnam),
( ftnlen ) fCnameLen,
( ftnlen ) fCdeclLen );
/*
Clean up all of our dynamically allocated arrays.
*/
free ( fCnameArr );
free ( fCdeclArr );
/*
Map segno to C style range.
*/
(*segno)--;
chkout_c ( "ekbseg_c" );
} /* End ekbseg_c */
//------------------------------------------------------------------------------
void SpiceOrbitKernelReader::GetCoverageStartAndEnd(StringArray &kernels,
Integer forNaifId,
Real &start,
Real &end)
{
// first check to see if a kernel specified is not loaded; if not,
// try to load it
for (unsigned int ii = 0; ii < kernels.size(); ii++)
if (!IsLoaded(kernels.at(ii))) LoadKernel(kernels.at(ii));
SpiceInt idSpice = forNaifId;
SpiceInt arclen = 4;
SpiceInt typlen = 5;
bool firstInt = true;
bool idOnKernel = false;
ConstSpiceChar *kernelName = NULL;
SpiceInt objId = 0;
SpiceInt numInt = 0;
SpiceChar *kernelType;
SpiceChar *arch;
SpiceDouble b;
SpiceDouble e;
Real bA1;
Real eA1;
SPICEINT_CELL(ids, 200);
SPICEDOUBLE_CELL(cover, 200000);
char kStr[5] = " ";
char aStr[4] = " ";
// look through each kernel
for (unsigned int ii = 0; ii < kernels.size(); ii++)
{
#ifdef DEBUG_SPK_COVERAGE
MessageInterface::ShowMessage(wxT("Checking coverage for ID %d on kernel %s\n"),
forNaifId, (kernels.at(ii)).c_str());
#endif
kernelName = kernels[ii].char_str();
// check the type of kernel
arch = aStr;
kernelType = kStr;
getfat_c(kernelName, arclen, typlen, arch, kernelType);
if (failed_c())
{
ConstSpiceChar option[] = "LONG";
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error determining type of kernel \"");
errmsg += kernels.at(ii) + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
#ifdef DEBUG_SPK_COVERAGE
MessageInterface::ShowMessage(wxT("Kernel is of type %s\n"),
kernelType);
#endif
// only deal with SPK kernels
if (eqstr_c( kernelType, "spk" ))
{
spkobj_c(kernelName, &ids);
// get the list of objects (IDs) for which data exists in the SPK kernel
for (SpiceInt jj = 0; jj < card_c(&ids); jj++)
{
objId = SPICE_CELL_ELEM_I(&ids,jj);
#ifdef DEBUG_SPK_COVERAGE
MessageInterface::ShowMessage(wxT("Kernel contains data for object %d\n"),
(Integer) objId);
#endif
// look to see if this kernel contains data for the object we're interested in
if (objId == idSpice)
{
idOnKernel = true;
break;
}
}
// only deal with kernels containing data for the object we're interested in
if (idOnKernel)
{
#ifdef DEBUG_SPK_COVERAGE
MessageInterface::ShowMessage(wxT("Checking kernel %s for data for object %d\n"),
(kernels.at(ii)).c_str(), (Integer) objId);
#endif
scard_c(0, &cover); // reset the coverage cell
spkcov_c (kernelName, idSpice, &cover);
if (failed_c())
{
ConstSpiceChar option[] = "LONG";
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error determining coverage for SPK kernel \"");
errmsg += kernels.at(ii) + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
numInt = wncard_c(&cover);
#ifdef DEBUG_SPK_COVERAGE
MessageInterface::ShowMessage(wxT("Number of intervals found = %d\n"),
(Integer) numInt);
#endif
if ((firstInt) && (numInt > 0))
{
wnfetd_c(&cover, 0, &b, &e);
if (failed_c())
{
ConstSpiceChar option[] = "LONG";
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error getting interval times for SPK kernel \"");
errmsg += kernels.at(ii) + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
start = SpiceTimeToA1(b);
end = SpiceTimeToA1(e);
firstInt = false;
}
for (SpiceInt jj = 0; jj < numInt; jj++)
{
wnfetd_c(&cover, jj, &b, &e);
bA1 = SpiceTimeToA1(b);
eA1 = SpiceTimeToA1(e);
if (bA1 < start) start = bA1;
if (eA1 > end) end = eA1;
}
}
}
}
if (firstInt)
{
wxString errmsg(wxT(""));
errmsg << wxT("Error - no data available for body with NAIF ID ") << forNaifId << wxT(" on specified SPK kernels\n");
throw UtilityException(errmsg);
}
}
void swpool_c ( ConstSpiceChar * agent,
SpiceInt nnames,
SpiceInt lenvals,
const void * names )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
agent I The name of an agent to be notified after updates.
nnames I The number of variables to associate with agent.
lenvals I Length of strings in the names array.
names I Variable names whose update causes the notice.
-Detailed_Input
agent is the name of a routine or entry point (agency) that
will want to know when a some variables in the kernel
pool have been updated.
nnames is the number of kernel pool variable names that will
be associated with agent.
lenvals is the length of the strings in the array names,
including the null terminators.
names is an array of names of variables in the kernel pool.
Whenever any of these is updated, a notice will be
posted for agent so that one can quickly check
whether needed data has been modified.
-Detailed_Output
None.
-Parameters
None.
-Files
None.
-Exceptions
1) If sufficient room is not available to hold a name or new agent,
a routine in the call tree for this routine will signal an error.
2) If either of the input string pointers are null, the error
SPICE(NULLPOINTER) will be signaled.
3) If any input string agent has length zero, the error
SPICE(EMPTYSTRING) will be signaled.
4) The caller must pass a value indicating the length of the strings
in the names array. If this value is not at least 2, the error
SPICE(STRINGTOOSHORT) will be signaled.
-Particulars
The kernel pool is a convenient place to store a wide variety of
data needed by routines in CSPICE and routines that interface with
CSPICE routines. However, when a single name has a large quantity
of data associated with it, it becomes inefficient to constantly
query the kernel pool for values that are not updated on a frequent
basis.
This entry point allows a routine to instruct the kernel pool to
post a message whenever a particular value gets updated. In this
way, a routine can quickly determine whether or not data it requires
has been updated since the last time the data was accessed. This
makes it reasonable to buffer the data in local storage and update
it only when a variable in the kernel pool that affects this data
has been updated.
Note that swpool_c has a side effect. Whenever a call to swpool_c
is made, the agent specified in the calling sequence is added to the
list of agents that should be notified that an update of its
variables has occurred. In other words the code
swpool_c ( agent, nnames, lenvals, names );
cvpool_c ( agent, &update );
will always return update as SPICETRUE.
This feature allows for a slightly cleaner use of swpool_c and
cvpool_c as shown in the example below. Because swpool_c
automatically loads agent into the list of agents to notify of a
kernel pool update, you do not have to include the code for fetching
the initial values of the kernel variables in the initialization
portion of a subroutine. Instead, the code for the first fetch from
the pool is the same as the code for fetching when the pool is
updated.
-Examples
Suppose that you have an application subroutine, MYTASK, that
needs to access a large data set in the kernel pool. If this
data could be kept in local storage and kernel pool queries
performed only when the data in the kernel pool has been
updated, the routine can perform much more efficiently.
The code fragment below illustrates how you might make use of this
feature.
#include "SpiceUsr.h"
.
.
.
/.
On the first call to this routine establish those variables
that we will want to read from the kernel pool only when
new values have been assigned.
./
if ( first )
{
first = SPICEFALSE;
swpool_c ( "MYTASK", nnames, lenvals, names );
}
/.
If any of the variables has been updated, fetch them from the
kernel pool.
./
cvpool_c ( "MYTASK", &update );
if ( update )
{
for ( i = 0; i < NVAR; i++ )
{
gdpool_c( MYTASK_VAR[i], 1, NMAX, n[i], val[i], &found[i] );
}
}
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
W.L. Taber (JPL)
-Version
-CSPICE Version 1.3.0, 27-AUG-2002 (NJB)
Call to C2F_CreateStrArr_Sig replaced with call to C2F_MapStrArr.
-CSPICE Version 1.2.0, 28-AUG-2001 (NJB)
Const-qualified input array names.
-CSPICE Version 1.1.0, 14-FEB-2000 (NJB)
Calls to C2F_CreateStrArr replaced with calls to error-signaling
version of this routine: C2F_CreateStrArr_Sig.
-CSPICE Version 1.0.0, 05-JUN-1999 (NJB) (WLT)
-Index_Entries
Watch for an update to a kernel pool variable
Notify a routine of an update to a kernel pool variable
-&
*/
{ /* Begin swpool_c */
/*
Local variables
*/
SpiceChar * fCvalsArr;
SpiceInt fCvalsLen;
/*
Participate in error tracing.
*/
chkin_c ( "swpool_c" );
/*
Make sure the input string pointer for agent is non-null
and that the length is sufficient.
*/
CHKFSTR ( CHK_STANDARD, "swpool_c", agent );
/*
Make sure the input string pointer for the names array is non-null
and that the length lenvals is sufficient.
*/
CHKOSTR ( CHK_STANDARD, "swpool_c", names, lenvals );
/*
Create a Fortran-style string array.
*/
C2F_MapStrArr ( "swpool_c",
nnames, lenvals, names, &fCvalsLen, &fCvalsArr );
if ( failed_c() )
{
chkout_c ( "swpool_c" );
return;
}
/*
Call the f2c'd routine.
*/
swpool_ ( ( char * ) agent,
( integer * ) &nnames,
( char * ) fCvalsArr,
( ftnlen ) strlen(agent),
( ftnlen ) fCvalsLen );
/*
Free the dynamically allocated array.
*/
free ( fCvalsArr );
chkout_c ( "swpool_c" );
} /* End swpool_c */
//------------------------------------------------------------------------------
Rvector6 SpiceOrbitKernelReader::GetTargetState(const wxString &targetName,
const Integer targetNAIFId,
const A1Mjd &atTime,
const wxString &observingBodyName,
const wxString &referenceFrame,
const wxString &aberration)
{
#ifdef DEBUG_SPK_READING
MessageInterface::ShowMessage(
wxT("Entering SPKReader::GetTargetState with target = %s, naifId = %d, time = %12.10f, observer = %s\n"),
targetName.c_str(), targetNAIFId, atTime.Get(), observingBodyName.c_str());
Real start, end;
GetCoverageStartAndEnd(loadedKernels, targetNAIFId, start, end);
MessageInterface::ShowMessage(wxT(" coverage for object %s : %12.10f --> %12.10f\n"),
targetName.c_str(), start, end);
#endif
wxString targetNameToUse = GmatStringUtil::ToUpper(targetName);
if (targetNameToUse == wxT("LUNA")) // We use Luna, instead of Moon, for GMAT
targetNameToUse = wxT("MOON");
if (targetNameToUse == wxT("SOLARSYSTEMBARYCENTER"))
targetNameToUse = wxT("SSB");
objectNameSPICE = targetNameToUse.char_str();
observingBodyNameSPICE = observingBodyName.char_str();
referenceFrameSPICE = referenceFrame.char_str();
aberrationSPICE = aberration.char_str();
// convert time to Ephemeris Time (TDB)
etSPICE = A1ToSpiceTime(atTime.Get());
naifIDSPICE = targetNAIFId;
boddef_c(objectNameSPICE, naifIDSPICE); // CSPICE method to set NAIF ID for an object
#ifdef DEBUG_SPK_READING
MessageInterface::ShowMessage(wxT("SET NAIF Id for object %s to %d\n"),
targetNameToUse.c_str(), targetNAIFId);
// MessageInterface::ShowMessage(
// wxT("In SPKReader::Converted (to TBD) time = %12.10f\n"), etMjdAtTime);
// MessageInterface::ShowMessage(wxT(" then the full JD = %12.10f\n"),
// (etMjdAtTime + GmatTimeConstants::JD_JAN_5_1941));
MessageInterface::ShowMessage(wxT("So time passed to SPICE is %12.14f\n"), (Real) etSPICE);
#endif
SpiceDouble state[6];
SpiceDouble oneWayLightTime;
spkezr_c(objectNameSPICE, etSPICE, referenceFrameSPICE, aberrationSPICE,
observingBodyNameSPICE, state, &oneWayLightTime);
#ifdef DEBUG_SPK_PLANETS
Real ttMjdAtTime = TimeConverterUtil::Convert(atTime.Get(), TimeConverterUtil::A1MJD,
TimeConverterUtil::TTMJD, GmatTimeConstants::JD_JAN_5_1941);
// Real etJd = etMjdAtTime + GmatTimeConstants::JD_JAN_5_1941;
Real ttJd = ttMjdAtTime + GmatTimeConstants::JD_JAN_5_1941;
MessageInterface::ShowMessage(wxT("Asking CSPICE for state of body %s, with observer %s, referenceFrame %s, and aberration correction %s\n"),
objectNameSPICE, observingBodyNameSPICE, referenceFrameSPICE, aberrationSPICE);
MessageInterface::ShowMessage(
wxT(" Body: %s TT Time: %12.10f TDB Time: %12.10f state: %12.10f %12.10f %12.10f %12.10f %12.10f %12.10f\n"),
targetName.c_str(), ttJd, /*etJd,*/ state[0], state[1], state[2], state[3], state[4], state[5]);
#endif
if (failed_c())
{
// ConstSpiceChar option[] = wxT("SHORT"); // retrieve short error message, for now
// SpiceInt numChar = MAX_SHORT_MESSAGE;
// SpiceChar err[MAX_SHORT_MESSAGE];
ConstSpiceChar option[] = "LONG"; // retrieve long error message, for now
SpiceInt numChar = MAX_LONG_MESSAGE_VALUE;
//SpiceChar err[MAX_LONG_MESSAGE_VALUE];
SpiceChar *err = new SpiceChar[MAX_LONG_MESSAGE_VALUE];
getmsg_c(option, numChar, err);
wxString errStr(wxString::FromAscii(err));
wxString errmsg = wxT("Error getting state for body \"");
errmsg += targetName + wxT("\". Message received from CSPICE is: ");
errmsg += errStr + wxT("\n");
reset_c();
delete [] err;
throw UtilityException(errmsg);
}
#ifdef DEBUG_SPK_READING
MessageInterface::ShowMessage(
wxT("In SPKReader::Called spkezr_c and got state out\n"));
#endif
Rvector6 r6(state[0],state[1],state[2],state[3],state[4],state[5]);
return r6;
}
void gfuds_c ( void ( * udfunc ) ( SpiceDouble et,
SpiceDouble * value ),
void ( * udqdec ) ( void ( * udfunc )
( SpiceDouble et,
SpiceDouble * value ),
SpiceDouble et,
SpiceBoolean * isdecr ),
ConstSpiceChar * relate,
SpiceDouble refval,
SpiceDouble adjust,
SpiceDouble step,
SpiceInt nintvls,
SpiceCell * cnfine,
SpiceCell * result )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
udfunc I Name of the routine that computes the scalar value
of interest at some time.
udqdec I Name of the routine that computes whether the
current state is decreasing.
relate I Operator that either looks for an extreme value
(max, min, local, absolute) or compares the
geometric quantity value and a number.
refval I Value used as reference for geometric quantity
condition.
adjust I Allowed variation for absolute extremal
geometric conditions.
step I Step size used for locating extrema and roots.
nintvls I Workspace window interval count
cnfine I-O SPICE window to which the search is restricted.
result O SPICE window containing results.
-Detailed_Input
udfunc the name of the external routine that returns the
value of the scalar quantity of interest at time ET.
The calling sequence for "udfunc" is:
udfunc ( et, &value )
where:
et an input double precision value
representing the TDB ephemeris seconds time
at which to determine the scalar value.
value is the value of the geometric quantity
at 'et'.
udqdec the name of the external routine that determines if
the scalar quantity calculated by "udfunc" is decreasing.
The calling sequence:
udqdec ( et, &isdecr )
where:
et an input double precision value representing
the TDB ephemeris seconds time at at which
to determine the time derivative of 'udfunc'.
isdecr a logical variable indicating whether
or not the scalar value returned by udfunc
is decreasing. 'isdecr' returns true if the
time derivative of "udfunc" at 'et' is negative.
relate the scalar string comparison operator indicating
the numeric constraint of interest. Values are:
">" value of scalar quantity greater than some
reference (refval).
"=" value of scalar quantity equal to some
reference (refval).
"<" value of scalar quantity less than some
reference (refval).
"ABSMAX" The scalar quantity is at an absolute
maximum.
"ABSMIN" The scalar quantity is at an absolute
minimum.
"LOCMAX" The scalar quantity is at a local
maximum.
"LOCMIN" The scalar quantity is at a local
minimum.
The caller may indicate that the region of interest
is the set of time intervals where the quantity is
within a specified distance of an absolute extremum.
The argument 'adjust' (described below) is used to
specified this distance.
Local extrema are considered to exist only in the
interiors of the intervals comprising the confinement
window: a local extremum cannot exist at a boundary
point of the confinement window.
relate is insensitive to case, leading and
trailing blanks.
refval is the reference value used to define an equality or
inequality to satisfied by the scalar quantity.
The units of refval are those of the scalar quantity.
adjust the amount by which the quantity is allowed to vary
from an absolute extremum.
If the search is for an absolute minimum is performed,
the resulting window contains time intervals when the
geometric quantity value has values between ABSMIN and
ABSMIN + adjust.
If the search is for an absolute maximum, the
corresponding range is between ABSMAX - adjust and
ABSMAX.
'adjust' is not used for searches for local extrema,
equality or inequality conditions and must have value
zero for such searches.
step the double precision time step size to use in
the search.
'step' must be short enough to for a search using this
step size to locate the time intervals where the
scalar quantity function is monotone increasing or
decreasing. However, 'step' must not be *too* short,
or the search will take an
The choice of 'step' affects the completeness but not
the precision of solutions found by this routine; the
precision is controlled by the convergence tolerance.
See the discussion of the parameter SPICE_GF_CNVTOL for
details.
'step' has units of TDB seconds.
nintvls an integer value specifying the number of intervals in the
the internal workspace array used by this routine. 'nintvls'
should be at least as large as the number of intervals
within the search region on which the specified observer-target
vector coordinate function is monotone increasing or decreasing.
It does no harm to pick a value of 'nintvls' larger than the
minimum required to execute the specified search, but if chosen
too small, the search will fail.
cnfine a double precision SPICE window that confines the time
period over which the specified search is conducted.
cnfine may consist of a single interval or a collection
of intervals.
In some cases the confinement window can be used to
greatly reduce the time period that must be searched
for the desired solution. See the Particulars section
below for further discussion.
See the Examples section below for a code example
that shows how to create a confinement window.
-Detailed_Output
cnfine is the input confinement window, updated if necessary
so the control area of its data array indicates the
window's size and cardinality. The window data are
unchanged.
result is a SPICE window representing the set of time
intervals, within the confinement period, when the
specified geometric event occurs.
If `result' is non-empty on input, its contents
will be discarded before gfuds_c conducts its
search.
-Parameters
None.
-Exceptions
1) In order for this routine to produce correct results,
the step size must be appropriate for the problem at hand.
Step sizes that are too large may cause this routine to miss
roots; step sizes that are too small may cause this routine
to run unacceptably slowly and in some cases, find spurious
roots.
This routine does not diagnose invalid step sizes, except
that if the step size is non-positive, an error is signaled
by a routine in the call tree of this routine.
2) Due to numerical errors, in particular,
- Truncation error in time values
- Finite tolerance value
- Errors in computed geometric quantities
it is *normal* for the condition of interest to not always be
satisfied near the endpoints of the intervals comprising the
result window.
The result window may need to be contracted slightly by the
caller to achieve desired results. The SPICE window routine
wncond_c can be used to contract the result window.
3) If an error (typically cell overflow) occurs while performing
window arithmetic, the error will be diagnosed by a routine
in the call tree of this routine.
4) If the relational operator `relate' is not recognized, an
error is signaled by a routine in the call tree of this
routine.
5) If 'adjust' is negative, the error SPICE(VALUEOUTOFRANGE) will
signal from a routine in the call tree of this routine.
A non-zero value for 'adjust' when 'relate' has any value other than
"ABSMIN" or "ABSMAX" causes the error SPICE(INVALIDVALUE) to
signal from a routine in the call tree of this routine.
6) If required ephemerides or other kernel data are not
available, an error is signaled by a routine in the call tree
of this routine.
7) If the workspace interval count is less than 1, the error
SPICE(VALUEOUTOFRANGE) will be signaled.
8) If the required amount of workspace memory cannot be
allocated, the error SPICE(MALLOCFAILURE) will be
signaled.
9) If any input string argument pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
10) If any input string argument is empty, the error
SPICE(EMPTYSTRING) will be signaled.
11) If either input cell has type other than SpiceDouble,
the error SPICE(TYPEMISMATCH) is signaled.
-Files
Appropriate kernels must be loaded by the calling program before
this routine is called.
If the scalar function requires access to ephemeris data:
- SPK data: ephemeris data for any body over the
time period defined by the confinement window must be
loaded. If aberration corrections are used, the states of
target and observer relative to the solar system barycenter
must be calculable from the available ephemeris data.
Typically ephemeris data are made available by loading one
or more SPK files via furnsh_c.
- If non-inertial reference frames are used, then PCK
files, frame kernels, C-kernels, and SCLK kernels may be
needed.
In all cases, kernel data are normally loaded once per program
run, NOT every time this routine is called.
-Particulars
This routine provides a simpler, but less flexible interface
than does the routine zzgfrel_ for conducting searches for events
corresponding to an arbitrary user defined scalar quantity
function. Applications that require support for progress
reporting, interrupt handling, non-default step or refinement
functions, or non-default convergence tolerance should call
zzgfrel_ rather than this routine.
This routine determines a set of one or more time intervals
within the confinement window when the scalar function
satisfies a caller-specified constraint. The resulting set of
intervals is returned as a SPICE window.
udqdec Default Template
=======================
The user must supply a routine to determine whether sign of the
time derivative of udfunc is positive or negative at 'et'. For
cases where udfunc is numerically well behaved, the user
may find it convenient to use a routine based on the below
template. uddc_c determines the truth of the expression
d (udfunc)
-- < 0
dt
using the library routine uddf_c to numerically calculate the
derivative of udfunc using a three-point estimation. Use
of gfdecr requires only changing the "udfunc" argument
to that of the user provided scalar function passed to gfuds_c
and defining the differential interval size, 'dt'. Please see
the Examples section for an example of gfdecr use.
void gfdecr ( SpiceDouble et, SpiceBoolean * isdecr )
{
SpiceDouble dt = h, double precision interval size;
uddc_c( udfunc, uddf_c, et, dt, isdecr );
return;
}
Below we discuss in greater detail aspects of this routine's
solution process that are relevant to correct and efficient
use of this routine in user applications.
The Search Process
==================
Regardless of the type of constraint selected by the caller, this
routine starts the search for solutions by determining the time
periods, within the confinement window, over which the specified
scalar function is monotone increasing and monotone
decreasing. Each of these time periods is represented by a SPICE
window. Having found these windows, all of the quantity
function's local extrema within the confinement window are known.
Absolute extrema then can be found very easily.
Within any interval of these "monotone" windows, there will be at
most one solution of any equality constraint. Since the boundary
of the solution set for any inequality constraint is the set
of points where an equality constraint is met, the solutions of
both equality and inequality constraints can be found easily
once the monotone windows have been found.
Step Size
=========
The monotone windows (described above) are found using a two-step
search process. Each interval of the confinement window is
searched as follows: first, the input step size is used to
determine the time separation at which the sign of the rate of
change of quantity function will be sampled. Starting at
the left endpoint of an interval, samples will be taken at each
step. If a change of sign is found, a root has been bracketed; at
that point, the time at which the time derivative of the quantity
function is zero can be found by a refinement process, for
example, using a binary search.
Note that the optimal choice of step size depends on the lengths
of the intervals over which the quantity function is monotone:
the step size should be shorter than the shortest of these
intervals (within the confinement window).
The optimal step size is *not* necessarily related to the lengths
of the intervals comprising the result window. For example, if
the shortest monotone interval has length 10 days, and if the
shortest result window interval has length 5 minutes, a step size
of 9.9 days is still adequate to find all of the intervals in the
result window. In situations like this, the technique of using
monotone windows yields a dramatic efficiency improvement over a
state-based search that simply tests at each step whether the
specified constraint is satisfied. The latter type of search can
miss solution intervals if the step size is shorter than the
shortest solution interval.
Having some knowledge of the relative geometry of the targets and
observer can be a valuable aid in picking a reasonable step size.
In general, the user can compensate for lack of such knowledge by
picking a very short step size; the cost is increased computation
time.
Note that the step size is not related to the precision with which
the endpoints of the intervals of the result window are computed.
That precision level is controlled by the convergence tolerance.
Convergence Tolerance
=====================
Once a root has been bracketed, a refinement process is used to
narrow down the time interval within which the root must lie.
This refinement process terminates when the location of the root
has been determined to within an error margin called the
"convergence tolerance." The convergence tolerance used by this
routine is set via the parameter SPICE_GF_CNVTOL.
The value of SPICE_GF_CNVTOL is set to a "tight" value so that the
tolerance doesn't become the limiting factor in the accuracy of
solutions found by this routine. In general the accuracy of input
data will be the limiting factor.
Making the tolerance tighter than SPICE_GF_CNVTOL is unlikely to
be useful, since the results are unlikely to be more accurate.
Making the tolerance looser will speed up searches somewhat,
since a few convergence steps will be omitted. However, in most
cases, the step size is likely to have a much greater affect
on processing time than would the convergence tolerance.
The Confinement Window
======================
The simplest use of the confinement window is to specify a time
interval within which a solution is sought. However, the
confinement window can, in some cases, be used to make searches
more efficient. Sometimes it's possible to do an efficient search
to reduce the size of the time period over which a relatively
slow search of interest must be performed.
-Examples
The numerical results shown for these examples may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
Conduct a search on the range-rate of the vector from the Sun
to the Moon. Define a function to calculate the value.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: standard.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
\begindata
KERNELS_TO_LOAD = ( 'de414.bsp',
'pck00008.tpc',
'naif0009.tls' )
\begintext
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SpiceUsr.h"
#include "SpiceZfc.h"
#include "SpiceZad.h"
#define MAXWIN 20000
#define TIMFMT "YYYY-MON-DD HR:MN:SC.###"
#define TIMLEN 41
#define NLOOPS 7
void gfq ( SpiceDouble et, SpiceDouble * value );
void gfdecrx ( void ( * udfunc ) ( SpiceDouble et,
SpiceDouble * value ),
SpiceDouble et,
SpiceBoolean * isdecr );
doublereal dvnorm_(doublereal *state);
int main( int argc, char **argv )
{
/.
Create the needed windows. Note, one interval
consists of two values, so the total number
of cell values to allocate is twice
the number of intervals.
./
SPICEDOUBLE_CELL ( result, 2*MAXWIN );
SPICEDOUBLE_CELL ( cnfine, 2 );
SpiceDouble begtim;
SpiceDouble endtim;
SpiceDouble step;
SpiceDouble adjust;
SpiceDouble refval;
SpiceDouble beg;
SpiceDouble end;
SpiceChar begstr [ TIMLEN ];
SpiceChar endstr [ TIMLEN ];
SpiceInt count;
SpiceInt i;
SpiceInt j;
ConstSpiceChar * relate [NLOOPS] = { "=",
"<",
">",
"LOCMIN",
"ABSMIN",
"LOCMAX",
"ABSMAX"
};
printf( "Compile date %s, %s\n\n", __DATE__, __TIME__ );
/.
Load kernels.
./
furnsh_c( "standard.tm" );
/.
Store the time bounds of our search interval in the 'cnfine'
confinement window.
./
str2et_c( "2007 JAN 01", &begtim );
str2et_c( "2007 APR 01", &endtim );
wninsd_c ( begtim, endtim, &cnfine );
/.
Search using a step size of 1 day (in units of seconds). The reference
value is .3365 km/s. We're not using the adjustment feature, so
we set 'adjust' to zero.
./
step = spd_c();
adjust = 0.;
refval = .3365;
for ( j = 0; j < NLOOPS; j++ )
{
printf ( "Relation condition: %s \n", relate[j] );
/.
Perform the search. The SPICE window 'result' contains
the set of times when the condition is met.
./
gfuds_c ( gfq,
gfdecrx,
relate[j],
refval,
adjust,
step,
MAXWIN,
&cnfine,
&result );
count = wncard_c( &result );
/.
Display the results.
./
if (count == 0 )
{
printf ( "Result window is empty.\n\n" );
}
else
{
for ( i = 0; i < count; i++ )
{
/.
Fetch the endpoints of the Ith interval
of the result window.
./
wnfetd_c ( &result, i, &beg, &end );
timout_c ( beg, TIMFMT, TIMLEN, begstr );
timout_c ( end, TIMFMT, TIMLEN, endstr );
printf ( "Start time, drdt = %s \n", begstr );
printf ( "Stop time, drdt = %s \n", endstr );
}
}
printf("\n");
}
kclear_c();
return( 0 );
}
/.
The user defined functions required by GFUDS.
gfq for udfunc
gfdecr for udqdec
./
/.
-Procedure Procedure gfq
./
void gfq ( SpiceDouble et, SpiceDouble * value )
/.
-Abstract
User defined geometric quantity function. In this case,
the range from the sun to the Moon at TDB time 'et'.
./
{
/. Initialization ./
SpiceInt targ = 301;
SpiceInt obs = 10;
SpiceChar * ref = "J2000";
SpiceChar * abcorr = "NONE";
SpiceDouble state [6];
SpiceDouble lt;
/.
Retrieve the vector from the Sun to the Moon in the J2000
frame, without aberration correction.
./
spkez_c ( targ, et, ref, abcorr, obs, state, < );
/.
Calculate the scalar range rate corresponding the
'state' vector.
./
*value = dvnorm_( state );
return;
}
/.
-Procedure gfdecrx
./
void gfdecrx ( void ( * udfunc ) ( SpiceDouble et,
SpiceDouble * value ),
SpiceDouble et,
SpiceBoolean * isdecr )
/.
-Abstract
User defined function to detect if the function derivative
is negative (the function is decreasing) at TDB time 'et'.
./
{
SpiceDouble dt = 10.;
/.
Determine if "udfunc" is decreasing at 'et'.
uddc_c - the GF function to determine if
the derivative of the user defined
function is negative at 'et'.
uddf_c - the SPICE function to numerically calculate the
derivative of 'udfunc' at 'et' for the
interval [et-dt, et+dt].
./
uddc_c( udfunc, et, dt, isdecr );
return;
}
The program outputs:
Relation condition: =
Start time, drdt = 2007-JAN-02 00:35:19.574
Stop time, drdt = 2007-JAN-02 00:35:19.574
Start time, drdt = 2007-JAN-19 22:04:54.899
Stop time, drdt = 2007-JAN-19 22:04:54.899
Start time, drdt = 2007-FEB-01 23:30:13.428
Stop time, drdt = 2007-FEB-01 23:30:13.428
Start time, drdt = 2007-FEB-17 11:10:46.540
Stop time, drdt = 2007-FEB-17 11:10:46.540
Start time, drdt = 2007-MAR-04 15:50:19.929
Stop time, drdt = 2007-MAR-04 15:50:19.929
Start time, drdt = 2007-MAR-18 09:59:05.959
Stop time, drdt = 2007-MAR-18 09:59:05.959
Relation condition: <
Start time, drdt = 2007-JAN-02 00:35:19.574
Stop time, drdt = 2007-JAN-19 22:04:54.899
Start time, drdt = 2007-FEB-01 23:30:13.428
Stop time, drdt = 2007-FEB-17 11:10:46.540
Start time, drdt = 2007-MAR-04 15:50:19.929
Stop time, drdt = 2007-MAR-18 09:59:05.959
Relation condition: >
Start time, drdt = 2007-JAN-01 00:00:00.000
Stop time, drdt = 2007-JAN-02 00:35:19.574
Start time, drdt = 2007-JAN-19 22:04:54.899
Stop time, drdt = 2007-FEB-01 23:30:13.428
Start time, drdt = 2007-FEB-17 11:10:46.540
Stop time, drdt = 2007-MAR-04 15:50:19.929
Start time, drdt = 2007-MAR-18 09:59:05.959
Stop time, drdt = 2007-APR-01 00:00:00.000
Relation condition: LOCMIN
Start time, drdt = 2007-JAN-11 07:03:58.988
Stop time, drdt = 2007-JAN-11 07:03:58.988
Start time, drdt = 2007-FEB-10 06:26:15.439
Stop time, drdt = 2007-FEB-10 06:26:15.439
Start time, drdt = 2007-MAR-12 03:28:36.404
Stop time, drdt = 2007-MAR-12 03:28:36.404
Relation condition: ABSMIN
Start time, drdt = 2007-JAN-11 07:03:58.988
Stop time, drdt = 2007-JAN-11 07:03:58.988
Relation condition: LOCMAX
Start time, drdt = 2007-JAN-26 02:27:33.766
Stop time, drdt = 2007-JAN-26 02:27:33.766
Start time, drdt = 2007-FEB-24 09:35:07.816
Stop time, drdt = 2007-FEB-24 09:35:07.816
Start time, drdt = 2007-MAR-25 17:26:56.150
Stop time, drdt = 2007-MAR-25 17:26:56.150
Relation condition: ABSMAX
Start time, drdt = 2007-MAR-25 17:26:56.150
Stop time, drdt = 2007-MAR-25 17:26:56.150
-Restrictions
1) Any kernel files required by this routine must be loaded
before this routine is called.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
E.D. Wright (JPL)
-Version
-CSPICE Version 1.0.0, 22-FEB-2010 (EDW)
-Index_Entries
GF user defined scalar function search
-&
*/
{ /* Begin gfuds_c */
/*
Local variables
*/
doublereal * work;
static SpiceInt nw = SPICE_GF_NWMAX;
SpiceInt nBytes;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "gfuds_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2 ( CHK_STANDARD, "gfuds_c", SPICE_DP, cnfine, result );
/*
Initialize the input cells if necessary.
*/
CELLINIT2 ( cnfine, result );
/*
Check the other input strings to make sure each pointer is non-null
and each string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "gfuds_c", relate );
/*
Store the input function pointers so these functions can be
called by the GF adapters.
*/
zzadsave_c ( UDFUNC, (void *)(udfunc) );
zzadsave_c ( UDQDEC, (void *)(udqdec) );
/*
Check the workspace size; some mallocs have a violent
dislike for negative allocation amounts. To be safe,
rule out a count of zero intervals as well.
*/
if ( nintvls < 1 )
{
setmsg_c ( "The specified workspace interval count # was "
"less than the minimum allowed value of one (1)." );
errint_c ( "#", nintvls );
sigerr_c ( "SPICE(VALUEOUTOFRANGE)" );
chkout_c ( "gfuds_c" );
return;
}
/*
Allocate the workspace. 'nintvls' indicates the maximum number of
intervals returned in 'result'. An interval consists of
two values.
*/
nintvls = 2 * nintvls;
nBytes = (nintvls + SPICE_CELL_CTRLSZ ) * nw * sizeof(SpiceDouble);
work = (doublereal *) alloc_SpiceMemory( nBytes );
if ( !work )
{
setmsg_c ( "Workspace allocation of # bytes failed due to "
"malloc failure" );
errint_c ( "#", nBytes );
sigerr_c ( "SPICE(MALLOCFAILED)" );
chkout_c ( "gfuds_c" );
return;
}
/*
Let the f2c'd routine do the work.
We pass the adapter functions, not those provided as inputs,
to the f2c'd routine:
zzadfunc_c adapter for udfunc
zzadqdec_c '' udqdec
*/
(void) gfuds_( ( U_fp ) zzadfunc_c,
( U_fp ) zzadqdec_c,
( char * ) relate,
( doublereal * ) &refval,
( doublereal * ) &adjust,
( doublereal * ) &step,
( doublereal * ) (cnfine->base),
( integer * ) &nintvls,
( integer * ) &nw,
( doublereal * ) work,
( doublereal * ) (result->base),
( ftnlen ) strlen(relate) );
/*
Always free dynamically allocated memory.
*/
free_SpiceMemory( work );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, result );
}
ALLOC_CHECK;
chkout_c ( "gfuds_c" );
} /* End gfuds_c */
void dafac_c ( SpiceInt handle,
SpiceInt n,
SpiceInt lenvals,
const void * buffer )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
handle I handle of a DAF opened with write access.
n I Number of comments to put into the comment area.
lenvals I Length of elements
buffer I Buffer of comments to put into the comment area.
-Detailed_Input
handle is the file handle of a binary DAF which has been opened
with write access.
n is the number of rows in the array `buffer'. This is
also the number of comment lines in `buffer' that are to be
added to the comment area of the binary DAF attached to
`handle'.
buffer A string buffer containing comments which are to be added
to the comment area of the binary DAF attached to `handle'.
buffer should be declared by the caller has follows:
SpiceChar buffer[n][lenvals];
Each row of the buffer should contain one comment line.
-Detailed_Output
None.
-Parameters
None.
-Exceptions
1) If the number of comments to be added is not positive, the
error SPICE(INVALIDARGUMENT) will be signaled.
2) If a non printing ASCII character is encountered in the
comments, the error SPICE(ILLEGALCHARACTER) will be signaled.
3) If the binary DAF file attached to HANDLE is not open with
write access an error will be signalled by a routine called by
this routine.
4) If the end of the comments cannot be found, i.e., the end of
comments marker is missing on the last comment record, the error
SPICE(BADCOMMENTAREA) will be signaled.
5) If the input pointer `buffer' is null, the error
SPICE(NULLPOINTER) will be signaled.
6) If the input buffer string length indicated by `lenvals'
is less than 2, the error SPICE(STRINGTOOSHORT) will be signaled.
-Files
See argument `handle' in $ Detailed_Input.
-Particulars
A binary DAF contains a data area which is reserved for storing
annotations or descriptive textual information about the data
contained in a file. This area is referred to as the ``comment
area'' of the file. The comment area of a DAF is a line oriented
medium for storing textual information. The comment area preserves
leading or embedded white space in the line(s) of text which are
stored so that the appearance of the information will be unchanged
when it is retrieved (extracted) at some other time. Trailing
blanks, however, are NOT preserved, due to the way that character
strings are represented in standard Fortran 77.
This routine will take a buffer of text lines and add (append) them
to the comment area of a binary DAF. If there are no comments in the
comment area of the file, then space will be allocated and the text
lines in `buffer' will be placed into the comment area. The text lines
may contain only printable ASCII characters (decimal values 32 -
126).
There is NO maximum length imposed on the significant portion of a
text line that may be placed into the comment area of a DAF. The
maximum length of a line stored in the comment area should be
reasonable, however, so that they may be easily extracted. A good
maximum value for this would be 255 characters, as this can easily
accommodate ``screen width'' lines as well as long lines which may
contain some other form of information.
-Examples
1) Let
handle be the handle for a DAF which has been opened with
write access.
n be the number of lines of text to be added to the
comment area of the binary DAF attached to handle.
lenvals be the length of the rows of a string buffer.
buffer is an array of text lines to be added to the comment
area of the binary DAF attached to handle. `buffer'
normally is declared
SpiceChar buffer [n][lenvals];
The call
dafac_c ( handle, n, lenvals, buffer );
will append the first n line(s) in `buffer' to the comment area
of the binary DAF attached to `handle'.
-Restrictions
1) This routine uses constants that are specific to the ASCII
character sequence. The results of using this routine with
a different character sequence are unpredictable.
2) This routine is only used to extract records on environments
whose characters are a single byte in size. Updates to this
routine and routines in its call tree may be required to
properly handle other cases.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
K.R. Gehringer (JPL)
-Version
-CSPICE Version 1.0.0, 16-NOV-2006 (NJB) (KRG)
-Index_Entries
add comments to a binary daf file
append comments to a daf file comment area
-&
*/
{ /* Begin dafac_c */
/*
Local variables
*/
SpiceChar * fCvalsArr;
SpiceInt fCvalsLen;
/*
Participate in error tracing.
*/
chkin_c ( "dafac_c" );
/*
Make sure the input string pointer for the `buffer' array is non-null
and that the length lenvals is sufficient.
*/
CHKOSTR ( CHK_STANDARD, "dafac_c", buffer, lenvals );
/*
The input buffer contains C-style strings; we must pass a
Fortran-style buffer to dafac_.
*/
C2F_MapStrArr ( "dafac_c",
n, lenvals, buffer, &fCvalsLen, &fCvalsArr );
if ( failed_c() )
{
chkout_c ( "dafac_c" );
return;
}
/*
Call the f2c'd routine.
*/
dafac_ ( ( integer * ) &handle,
( integer * ) &n,
( char * ) fCvalsArr,
( ftnlen ) fCvalsLen );
/*
Free the dynamically allocated array.
*/
free ( fCvalsArr );
chkout_c ( "dafac_c" );
} /* End dafac_c */
void ckcov_c ( ConstSpiceChar * ck,
SpiceInt idcode,
SpiceBoolean needav,
ConstSpiceChar * level,
SpiceDouble tol,
ConstSpiceChar * timsys,
SpiceCell * cover )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
ck I Name of CK file.
idcode I ID code of object.
needav I Flag indicating whether angular velocity is needed.
level I Coverage level: "SEGMENT" OR "INTERVAL".
tol I Tolerance in ticks.
timsys I Time system used to represent coverage.
cover I/O Window giving coverage for `idcode'.
-Detailed_Input
ck is the name of a C-kernel.
idcode is the integer ID code of an object, normally a
spacecraft structure or instrument, for which
pointing data are expected to exist in the specified
CK file.
needav is a logical variable indicating whether only
segments having angular velocity are to be considered
when determining coverage. When `needav' is
SPICETRUE, segments without angular velocity don't
contribute to the coverage window; when `needav' is
SPICEFALSE, all segments for `idcode' may contribute
to the coverage window.
level is the level (granularity) at which the coverage
is examined. Allowed values and corresponding
meanings are:
"SEGMENT" The output coverage window contains
intervals defined by the start and
stop times of segments for the object
designated by `idcode'.
"INTERVAL" The output coverage window contains
interpolation intervals of segments
for the object designated by
`idcode'. For type 1 segments, which
don't have interpolation intervals,
each epoch associated with a pointing
instance is treated as a singleton
interval; these intervals are added
to the coverage window.
All interpolation intervals are
considered to lie within the segment
bounds for the purpose of this
summary: if an interpolation
interval extends beyond the segment
coverage interval, only its
intersection with the segment
coverage interval is considered to
contribute to the total coverage.
tol is a tolerance value expressed in ticks of the
spacecraft clock associated with IDCODE. Before each
interval is inserted into the coverage window, the
interval is intersected with the segment coverage
interval, then if the intersection is non-empty, it
is expanded by `tol': the left endpoint of the
intersection interval is reduced by `tol' and the
right endpoint is increased by `tol'. Adjusted
interval endpoints, when expressed as encoded SCLK,
never are less than zero ticks. Any intervals that
overlap as a result of the expansion are merged.
The coverage window returned when tol > 0 indicates
the coverage provided by the file to the CK readers
ckgpav_c and ckgp_c when that value of `tol' is
passed to them as an input.
timsys is a string indicating the time system used in the
output coverage window. `timsys' may have the
values:
"SCLK" Elements of `cover' are expressed in
encoded SCLK ("ticks"), where the
clock is associated with the object
designated by `idcode'.
"TDB" Elements of `cover' are expressed as
seconds past J2000 TDB.
cover is an initialized CSPICE window data structure.
`cover' optionally may contain coverage data on
input; on output, the data already present in `cover'
will be combined with coverage found for the object
designated by `idcode' in the file `ck'.
If `cover' contains no data on input, its size and
cardinality still must be initialized.
-Detailed_Output
cover is a CSPICE window data structure which represents
the merged coverage for `idcode'. When the coverage
level is "INTERVAL", this is the set of time
intervals for which data for `idcode' are present in
the file `ck', merged with the set of time intervals
present in `cover' on input. The merged coverage is
represented as the union of one or more disjoint time
intervals. The window `cover' contains the pairs of
endpoints of these intervals.
When the coverage level is "SEGMENT", `cover' is
computed in a manner similar to that described above,
but the coverage intervals used in the computation
are those of segments rather than interpolation
intervals within segments.
When `tol' is > 0, the intervals comprising the
coverage window for `idcode' are expanded by `tol'
and any intervals overlapping as a result are merged.
The resulting window is returned in `cover'. The
expanded window in no case extends beyond the segment
bounds in either direction by more than `tol'.
The interval endpoints contained in `cover' are
encoded spacecraft clock times if `timsys' is "SCLK";
otherwise the times are converted from encoded
spacecraft clock to seconds past J2000 TDB.
See the Examples section below for a complete example
program showing how to retrieve the endpoints from
`cover'.
-Parameters
None.
-Exceptions
1) If the input file has transfer format, the error
SPICE(INVALIDFORMAT) is signaled.
2) If the input file is not a transfer file but has architecture
other than DAF, the error SPICE(BADARCHTYPE) is signaled.
3) If the input file is a binary DAF file of type other than
CK, the error SPICE(BADFILETYPE) is signaled.
4) If the CK file cannot be opened or read, the error will
be diagnosed by routines called by this routine. The output
window will not be modified.
5) If the size of the output window argument `cover' is
insufficient to contain the actual number of intervals in the
coverage window for `idcode', the error will be diagnosed by
routines called by this routine.
6) If `tol' is negative, the error SPICE(VALUEOUTOFRANGE) is
signaled.
7) If `level' is not recognized, the error SPICE(INVALIDOPTION)
is signaled.
8) If `timsys' is not recognized, the error SPICE(INVALIDOPTION)
is signaled.
9) If a time conversion error occurs, the error will be
diagnosed by a routine in the call tree of this routine.
10) If the output time system is TDB, the CK subsystem must be
able to map `idcode' to the ID code of the associated
spacecraft clock. If this mapping cannot be performed, the
error will be diagnosed by a routine in the call tree of this
routine.
11) The error SPICE(EMPTYSTRING) is signaled if any of the input
strings `ck', `level', or `timsys' do not contain at least one
character, since such an input string cannot be converted to a
Fortran-style string in this case.
12) The error SPICE(NULLPOINTER) is signaled if the if any of the input
strings `ck', `level', or `timsys' are null.
-Files
This routine reads a C-kernel.
If the output time system is "TDB", then a leapseconds kernel
and an SCLK kernel for the spacecraft clock associated with
`idcode' must be loaded before this routine is called.
If the ID code of the clock associated with `idcode' is not
equal to
idcode / 1000
then the kernel variable
CK_<idcode>_SCLK
must be present in the kernel pool to identify the clock
associated with `idcode'. This variable must contain the ID code
to be used for conversion between SCLK and TDB. Normally this
variable is provided in a text kernel loaded via furnsh_c.
-Particulars
This routine provides an API via which applications can determine
the coverage a specified CK file provides for a specified
object.
-Examples
1) Display the interval-level coverage for each object in a
specified CK file. Use tolerance of zero ticks. Do not request
angular velocity. Express the results in the TDB time system.
Find the set of objects in the file. Loop over the contents of
the ID code set: find the coverage for each item in the set and
display the coverage.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local parameters
./
#define FILSIZ 256
#define MAXIV 100000
#define WINSIZ ( 2 * MAXIV )
#define TIMLEN 51
#define MAXOBJ 1000
/.
Local variables
./
SPICEDOUBLE_CELL ( cover, WINSIZ );
SPICEINT_CELL ( ids, MAXOBJ );
SpiceChar ck [ FILSIZ ];
SpiceChar lsk [ FILSIZ ];
SpiceChar sclk [ FILSIZ ];
SpiceChar timstr [ TIMLEN ];
SpiceDouble b;
SpiceDouble e;
SpiceInt i;
SpiceInt j;
SpiceInt niv;
SpiceInt obj;
/.
Load a leapseconds kernel and SCLK kernel for output time
conversion. Note that we assume a single spacecraft clock is
associated with all of the objects in the CK.
./
prompt_c ( "Name of leapseconds kernel > ", FILSIZ, lsk );
furnsh_c ( lsk );
prompt_c ( "Name of SCLK kernel > ", FILSIZ, sclk );
furnsh_c ( sclk );
/.
Get name of CK file.
./
prompt_c ( "Name of CK file > ", FILSIZ, ck );
/.
Find the set of objects in the CK file.
./
ckobj_c ( ck, &ids );
/.
We want to display the coverage for each object. Loop over
the contents of the ID code set, find the coverage for
each item in the set, and display the coverage.
./
for ( i = 0; i < card_c( &ids ); i++ )
{
/.
Find the coverage window for the current object.
Empty the coverage window each time so we don't
include data for the previous object.
./
obj = SPICE_CELL_ELEM_I( &ids, i );
scard_c ( 0, &cover );
ckcov_c ( ck, obj, SPICEFALSE,
"INTERVAL", 0.0, "TDB", &cover );
/.
Get the number of intervals in the coverage window.
./
niv = wncard_c( &cover );
/.
Display a simple banner.
./
printf ( "%s\n", "========================================" );
printf ( "Coverage for object %ld\n", obj );
/.
Convert the coverage interval start and stop times to TDB
calendar strings.
./
for ( j = 0; j < niv; j++ )
{
/.
Get the endpoints of the jth interval.
./
wnfetd_c ( &cover, j, &b, &e );
/.
Convert the endpoints to TDB calendar
format time strings and display them.
./
timout_c ( b,
"YYYY MON DD HR:MN:SC.###### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "\n"
"Interval: %ld\n"
"Start: %s\n",
j,
timstr );
timout_c ( e,
"YYYY MON DD HR:MN:SC.###### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "Stop: %s\n", timstr );
}
printf ( "%s\n", "========================================" );
}
return ( 0 );
}
2) Find the segment-level coverage for the object designated by
IDCODE provided by the set of CK files loaded via a metakernel.
(The metakernel must also specify leapseconds and SCLK kernels.)
Use tolerance of zero ticks. Do not request angular velocity.
Express the results in the TDB time system.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local parameters
./
#define FILSIZ 256
#define LNSIZE 81
#define MAXCOV 100000
#define WINSIZ ( 2 * MAXCOV )
#define TIMLEN 51
/.
Local variables
./
SPICEDOUBLE_CELL ( cover, WINSIZ );
SpiceBoolean found;
SpiceChar file [ FILSIZ ];
SpiceChar idch [ LNSIZE ];
SpiceChar meta [ FILSIZ ];
SpiceChar source [ FILSIZ ];
SpiceChar timstr [ TIMLEN ];
SpiceChar type [ LNSIZE ];
SpiceDouble b;
SpiceDouble e;
SpiceInt count;
SpiceInt handle;
SpiceInt i;
SpiceInt idcode;
SpiceInt niv;
/.
Prompt for the metakernel name; load the metakernel.
The metakernel lists the CK files whose coverage
for `idcode' we'd like to determine. The metakernel
must also specify a leapseconds kernel and an SCLK
kernel for the clock associated with `idcode'.
./
prompt_c ( "Name of metakernel > ", FILSIZ, meta );
furnsh_c ( meta );
/.
Get the ID code of interest.
./
prompt_c ( "Enter ID code > ", LNSIZE, idch );
prsint_c ( idch, &idcode );
/.
Find out how many kernels are loaded. Loop over the
kernels: for each loaded CK file, add its coverage
for `idcode', if any, to the coverage window.
./
ktotal_c ( "CK", &count );
for ( i = 0; i < count; i++ )
{
kdata_c ( i, "CK", FILSIZ,
LNSIZE, FILSIZ, file,
type, source, &handle, &found );
ckcov_c ( file, idcode, SPICEFALSE,
"SEGMENT", 0.0, "TDB", &cover );
}
/.
Display results.
Get the number of intervals in the coverage window.
./
niv = wncard_c( &cover );
/.
Display a simple banner.
./
printf ( "\nCoverage for object %ld\n", idcode );
/.
Convert the coverage interval start and stop times to TDB
calendar strings.
./
for ( i = 0; i < niv; i++ )
{
/.
Get the endpoints of the ith interval.
./
wnfetd_c ( &cover, i, &b, &e );
/.
Convert the endpoints to TDB calendar
format time strings and display them.
./
timout_c ( b,
"YYYY MON DD HR:MN:SC.###### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "\n"
"Interval: %ld\n"
"Start: %s\n",
i,
timstr );
timout_c ( e,
"YYYY MON DD HR:MN:SC.###### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "Stop: %s\n", timstr );
}
return ( 0 );
}
-Restrictions
1) When this routine is used to accumulate coverage for `idcode'
provided by multiple CK files, the inputs `needav', `level', `tol',
and `timsys' must have the same values for all files in order
for the result to be meaningful.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.0.1, 30-NOV-2007 (NJB)
Corrected bug in first example program in header:
program now empties result window prior to collecting
data for each object. Updated examples to use wncard_c
rather than card_c. Updated second example to demonstrate
segment-level summary capability.
-CSPICE Version 1.0.0, 07-JAN-2005 (NJB)
-Index_Entries
get coverage window for ck object
-&
*/
{ /* Begin ckcov_c */
/*
Local variables
*/
logical need;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "ckcov_c" );
/*
Check the input string `ck' to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "ckcov_c", ck );
/*
Check the input string `level' to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "ckcov_c", level );
/*
Check the input string `timsys' to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "ckcov_c", timsys );
/*
Make sure cell data type is d.p.
*/
CELLTYPECHK ( CHK_STANDARD, "ckcov_c", SPICE_DP, cover );
/*
Initialize the cell if necessary.
*/
CELLINIT ( cover );
/*
Call the f2c'd Fortran routine.
*/
need = needav;
ckcov_ ( ( char * ) ck,
( integer * ) &idcode,
( logical * ) &need,
( char * ) level,
( doublereal * ) &tol,
( char * ) timsys,
( doublereal * ) (cover->base),
( ftnlen ) strlen(ck),
( ftnlen ) strlen(level),
( ftnlen ) strlen(timsys) );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, cover );
}
chkout_c ( "ckcov_c" );
} /* End ckcov_c */
void gfoclt_c ( ConstSpiceChar * occtyp,
ConstSpiceChar * front,
ConstSpiceChar * fshape,
ConstSpiceChar * fframe,
ConstSpiceChar * back,
ConstSpiceChar * bshape,
ConstSpiceChar * bframe,
ConstSpiceChar * abcorr,
ConstSpiceChar * obsrvr,
SpiceDouble step,
SpiceCell * cnfine,
SpiceCell * result )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
--------------- --- -------------------------------------------------
SPICE_GF_CNVTOL P Convergence tolerance.
occtyp I Type of occultation.
front I Name of body occulting the other.
fshape I Type of shape model used for front body.
fframe I Body-fixed, body-centered frame for front body.
back I Name of body occulted by the other.
bshape I Type of shape model used for back body.
bframe I Body-fixed, body-centered frame for back body.
abcorr I Aberration correction flag.
obsrvr I Name of the observing body.
step I Step size in seconds for finding occultation
events.
cnfine I-O SPICE window to which the search is restricted.
result O SPICE window containing results.
-Detailed_Input
occtyp indicates the type of occultation that is to be found.
Note that transits are considered to be a type of
occultation.
Supported values and corresponding definitions are:
"FULL" denotes the full occultation
of the body designated by
`back' by the body designated
by `front', as seen from
the location of the observer.
In other words, the occulted
body is completely invisible
as seen from the observer's
location.
"ANNULAR" denotes an annular
occultation: the body
designated by `front' blocks
part of, but not the limb of,
the body designated by `back',
as seen from the location of
the observer.
"PARTIAL" denotes a partial, non-annular
occultation: the body designated
by `front' blocks part, but not
all, of the limb of the body
designated by `back', as seen
from the location of the
observer.
"ANY" denotes any of the above three
types of occultations:
"PARTIAL", "ANNULAR", or
"FULL".
"ANY" should be used to search
for times when the body
designated by `front' blocks
any part of the body designated
by `back'.
The option "ANY" must be used
if either the front or back
target body is modeled as
a point.
Case and leading or trailing blanks are not
significant in the string `occtyp'.
front is the name of the target body that occults---that is,
passes in front of---the other. Optionally, you may
supply the integer NAIF ID code for the body as a
string. For example both "MOON" and "301" are
legitimate strings that designate the Moon.
Case and leading or trailing blanks are not
significant in the string `front'.
fshape is a string indicating the geometric model used to
represent the shape of the front target body. The
supported options are:
"ELLIPSOID" Use a triaxial ellipsoid model
with radius values provided via the
kernel pool. A kernel variable
having a name of the form
"BODYnnn_RADII"
where nnn represents the NAIF
integer code associated with the
body, must be present in the kernel
pool. This variable must be
associated with three numeric
values giving the lengths of the
ellipsoid's X, Y, and Z semi-axes.
"POINT" Treat the body as a single point.
When a point target is specified,
the occultation type must be
set to "ANY".
At least one of the target bodies `front' and `back' must
be modeled as an ellipsoid.
Case and leading or trailing blanks are not
significant in the string `fshape'.
fframe is the name of the body-fixed, body-centered reference
frame associated with the front target body. Examples
of such names are "IAU_SATURN" (for Saturn) and
"ITRF93" (for the Earth).
If the front target body is modeled as a point, `fframe'
should be left empty or blank.
Case and leading or trailing blanks bracketing a
non-blank frame name are not significant in the string
`fframe'.
back is the name of the target body that is occulted
by---that is, passes in back of---the other.
Optionally, you may supply the integer NAIF ID code
for the body as a string. For example both "MOON" and
"301" are legitimate strings that designate the Moon.
Case and leading or trailing blanks are not
significant in the string `back'.
bshape is the shape specification for the body designated by
`back'. The supported options are those for `fshape'. See
the description of `fshape' above for details.
bframe is the name of the body-fixed, body-centered reference
frame associated with the ``back'' target body.
Examples of such names are "IAU_SATURN" (for Saturn)
and "ITRF93" (for the Earth).
If the back target body is modeled as a point, `bframe'
should be left empty or blank.
Case and leading or trailing blanks bracketing a
non-blank frame name are not significant in the string
`bframe'.
abcorr indicates the aberration corrections to be applied to
the state of each target body to account for one-way
light time. Stellar aberration corrections are
ignored if specified, since these corrections don't
improve the accuracy of the occultation determination.
See the header of the SPICE routine spkezr_c for a
detailed description of the aberration correction
options. For convenience, the options supported by
this routine are listed below:
"NONE" Apply no correction.
"LT" "Reception" case: correct for
one-way light time using a Newtonian
formulation.
"CN" "Reception" case: converged
Newtonian light time correction.
"XLT" "Transmission" case: correct for
one-way light time using a Newtonian
formulation.
"XCN" "Transmission" case: converged
Newtonian light time correction.
Case and blanks are not significant in the string
`abcorr'.
obsrvr is the name of the body from which the occultation is
observed. Optionally, you may supply the integer NAIF
ID code for the body as a string.
Case and leading or trailing blanks are not
significant in the string `obsrvr'.
step is the step size to be used in the search. `step' must
be shorter than any interval, within the confinement
window, over which the specified condition is met. In
other words, `step' must be shorter than the shortest
occultation event that the user wishes to detect; `step'
must also be shorter than the shortest time interval
between two occultation events that occur within the
confinement window (see below). However, `step' must not
be *too* short, or the search will take an unreasonable
amount of time.
The choice of `step' affects the completeness but not the
precision of solutions found by this routine; the
precision is controlled by the convergence tolerance. See
the discussion of the parameter SPICE_GF_CNVTOL for
details.
`step' has units of TDB seconds.
cnfine is a SPICE window that confines the time period over
which the specified search is conducted. `cnfine' may
consist of a single interval or a collection of
intervals.
The endpoints of the time intervals comprising `cnfine'
are interpreted as seconds past J2000 TDB.
See the Examples section below for a code example
that shows how to create a confinement window.
-Detailed_Output
cnfine is the input confinement window, updated if necessary
so the control area of its data array indicates the
window's size and cardinality. The window data are
unchanged.
result is a SPICE window representing the set of time
intervals, within the confinement period, when the
specified occultation occurs.
The endpoints of the time intervals comprising `result'
are interpreted as seconds past J2000 TDB.
If `result' is non-empty on input, its contents
will be discarded before gfoclt_c conducts its
search.
-Parameters
SPICE_GF_CNVTOL
is the convergence tolerance used for finding endpoints
of the intervals comprising the result window.
SPICE_GF_CNVTOL is used to determine when binary searches
for roots should terminate: when a root is bracketed
within an interval of length SPICE_GF_CNVTOL, the root is
considered to have been found.
The accuracy, as opposed to precision, of roots found
by this routine depends on the accuracy of the input
data. In most cases, the accuracy of solutions will be
inferior to their precision.
SPICE_GF_CNVTOL is declared in the header file
SpiceGF.h
-Exceptions
1) In order for this routine to produce correct results,
the step size must be appropriate for the problem at hand.
Step sizes that are too large may cause this routine to miss
roots; step sizes that are too small may cause this routine
to run unacceptably slowly and in some cases, find spurious
roots.
This routine does not diagnose invalid step sizes, except
that if the step size is non-positive, the error
SPICE(INVALIDSTEPSIZE) will be signaled.
2) Due to numerical errors, in particular,
- Truncation error in time values
- Finite tolerance value
- Errors in computed geometric quantities
it is *normal* for the condition of interest to not always be
satisfied near the endpoints of the intervals comprising the
result window.
The result window may need to be contracted slightly by the
caller to achieve desired results. The SPICE window routine
wncond_c can be used to contract the result window.
3) If name of either target or the observer cannot be translated
to a NAIF ID code, the error will be diagnosed by a routine
in the call tree of this routine.
4) If the radii of a target body modeled as an ellipsoid cannot
be determined by searching the kernel pool for a kernel
variable having a name of the form
"BODYnnn_RADII"
where nnn represents the NAIF integer code associated with
the body, the error will be diagnosed by a routine in the
call tree of this routine.
5) If either of the target bodies `front' or `back' coincides with
the observer body `obsrvr', the error will be diagnosed by a
routine in the call tree of this routine.
6) If the body designated by `front' coincides with that
designated by `back', the error will be diagnosed by a routine
in the call tree of this routine.
7) If either of the body model specifiers `fshape' or `bshape'
is not recognized, the error will be diagnosed by a routine
in the call tree of this routine.
8) If both of the body model specifiers `fshape' and `bshape'
specify point targets, the error will be diagnosed by a
routine in the call tree of this routine.
9) If a target body-fixed reference frame associated with a
non-point target is not recognized, the error will be
diagnosed by a routine in the call tree of this routine.
10) If a target body-fixed reference frame is not centered at
the corresponding target body, the error will be
diagnosed by a routine in the call tree of this routine.
11) If the loaded kernels provide insufficient data to
compute any required state vector, the deficiency will
be diagnosed by a routine in the call tree of this routine.
12) If an error occurs while reading an SPK or other kernel file,
the error will be diagnosed by a routine in the call tree
of this routine.
13) If the output SPICE window `result' has insufficient capacity
to contain the number of intervals on which the specified
occultation condition is met, the error will be diagnosed
by a routine in the call tree of this routine.
14) If a point target is specified and the occultation
type is set to a valid value other than "ANY", the
error will be diagnosed by a routine in the call tree
of this routine.
15) Invalid occultation types will be diagnosed by a routine in
the call tree of this routine.
16) Invalid aberration correction specifications will be
diagnosed by a routine in the call tree of this routine.
17) If any input string argument pointer is null, the error
SPICE(NULLPOINTER) will be signaled.
18) If any input string argument, other than `fframe' or `bframe',
is empty, the error SPICE(EMPTYSTRING) will be signaled.
-Files
Appropriate SPICE kernels must be loaded by the calling program
before this routine is called.
The following data are required:
- SPK data: the calling application must load ephemeris data
for the target, source and observer that cover the time
period specified by the window `cnfine'. If aberration
corrections are used, the states of target and observer
relative to the solar system barycenter must be calculable
from the available ephemeris data. Typically ephemeris data
are made available by loading one or more SPK files via
furnsh_c.
- PCK data: bodies modeled as triaxial ellipsoids must have
semi-axis lengths provided by variables in the kernel pool.
Typically these data are made available by loading a text
PCK file via furnsh_c.
- FK data: if either of the reference frames designated by
`bframe' or `fframe' are not built in to the SPICE system,
one or more FKs specifying these frames must be loaded.
Kernel data are normally loaded once per program run, NOT every time
this routine is called.
-Particulars
This routine provides a simpler, but less flexible, interface
than does the CSPICE routine gfocce_c for conducting searches for
occultation events. Applications that require support for
progress reporting, interrupt handling, non-default step or
refinement functions, or non-default convergence tolerance should
call gfocce_c rather than this routine.
This routine determines a set of one or more time intervals
within the confinement window when a specified type of
occultation occurs. The resulting set of intervals is returned as
a SPICE window.
Below we discuss in greater detail aspects of this routine's
solution process that are relevant to correct and efficient
use of this routine in user applications.
The Search Process
==================
The search for occultations is treated as a search for state
transitions: times are sought when the state of the `back' body
changes from "not occulted" to "occulted" or vice versa.
Step Size
=========
Each interval of the confinement window is searched as follows:
first, the input step size is used to determine the time separation
at which the occultation state will be sampled. Starting at the left
endpoint of the interval, samples of the occultation state will be
taken at each step. If a state change is detected, a root has been
bracketed; at that point, the "root"--the time at which the state
change occurs---is found by a refinement process, for example, via
binary search.
Note that the optimal choice of step size depends on the lengths
of the intervals over which the occultation state is constant:
the step size should be shorter than the shortest occultation
duration and the shortest period between occultations, within
the confinement window.
Having some knowledge of the relative geometry of the targets and
observer can be a valuable aid in picking a reasonable step size.
In general, the user can compensate for lack of such knowledge by
picking a very short step size; the cost is increased computation
time.
Note that the step size is not related to the precision with which
the endpoints of the intervals of the result window are computed.
That precision level is controlled by the convergence tolerance.
Convergence Tolerance
=====================
Once a root has been bracketed, a refinement process is used to
narrow down the time interval within which the root must lie. This
refinement process terminates when the location of the root has been
determined to within an error margin called the "convergence
tolerance." The convergence tolerance used by this routine is set
via the parameter SPICE_GF_CNVTOL.
The value of SPICE_GF_CNVTOL is set to a "tight" value so that the
tolerance doesn't limit the accuracy of solutions found by this
routine. In general the accuracy of input data will be the limiting
factor.
To use a different tolerance value, a lower-level GF routine such as
gfocce_c must be called. Making the tolerance tighter than
SPICE_GF_CNVTOL is unlikely to be useful, since the results are
unlikely to be more accurate. Making the tolerance looser will speed
up searches somewhat, since a few convergence steps will be omitted.
However, in most cases, the step size is likely to have a much
greater effect on processing time than would the convergence
tolerance.
The Confinement Window
======================
The simplest use of the confinement window is to specify a time
interval within which a solution is sought.
The confinement window also can be used to restrict a search to
a time window over which required data (typically ephemeris
data, in the case of occultation searches) are known to be
available.
In some cases, the confinement window be used to make searches
more efficient. Sometimes it's possible to do an efficient search
to reduce the size of the time period over which a relatively
slow search of interest must be performed. See the "CASCADE"
example program in gf.req for a demonstration.
-Examples
The numerical results shown for these examples may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
1) Find occultations of the Sun by the Moon (that is, solar
eclipses) as seen from the center of the Earth over the month
December, 2001.
Use light time corrections to model apparent positions of Sun
and Moon. Stellar aberration corrections are not specified
because they don't affect occultation computations.
We select a step size of 3 minutes, which means we
ignore occultation events lasting less than 3 minutes,
if any exist.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: standard.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
\begindata
KERNELS_TO_LOAD = ( 'de421.bsp',
'pck00008.tpc',
'naif0009.tls' )
\begintext
Example code begins here.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local constants
./
#define TIMFMT "YYYY MON DD HR:MN:SC.###### (TDB)::TDB"
#define MAXWIN 200
#define TIMLEN 41
/.
Local variables
./
SPICEDOUBLE_CELL ( cnfine, MAXWIN );
SPICEDOUBLE_CELL ( result, MAXWIN );
SpiceChar * win0;
SpiceChar * win1;
SpiceChar begstr [ TIMLEN ];
SpiceChar endstr [ TIMLEN ];
SpiceDouble et0;
SpiceDouble et1;
SpiceDouble left;
SpiceDouble right;
SpiceDouble step;
SpiceInt i;
/.
Load kernels.
./
furnsh_c ( "standard.tm" );
/.
Obtain the TDB time bounds of the confinement
window, which is a single interval in this case.
./
win0 = "2001 DEC 01 00:00:00 TDB";
win1 = "2002 JAN 01 00:00:00 TDB";
str2et_c ( win0, &et0 );
str2et_c ( win1, &et1 );
/.
Insert the time bounds into the confinement
window.
./
wninsd_c ( et0, et1, &cnfine );
/.
Select a 3-minute step. We'll ignore any occultations
lasting less than 3 minutes. Units are TDB seconds.
./
step = 180.0;
/.
Perform the search.
./
gfoclt_c ( "any",
"moon", "ellipsoid", "iau_moon",
"sun", "ellipsoid", "iau_sun",
"lt", "earth", step,
&cnfine, &result );
if ( wncard_c(&result) == 0 )
{
printf ( "No occultation was found.\n" );
}
else
{
for ( i = 0; i < wncard_c(&result); i++ )
{
/.
Fetch and display each occultation interval.
./
wnfetd_c ( &result, i, &left, &right );
timout_c ( left, TIMFMT, TIMLEN, begstr );
timout_c ( right, TIMFMT, TIMLEN, endstr );
printf ( "Interval %ld\n"
" Start time: %s\n"
" Stop time: %s\n",
i, begstr, endstr );
}
}
return ( 0 );
}
When this program was executed on a PC/Linux/gcc platform, the
output was:
Interval 0
Start time: 2001 DEC 14 20:10:14.195952 (TDB)
Stop time: 2001 DEC 14 21:35:50.317994 (TDB)
2) Find occultations of Titan by Saturn or of Saturn by
Titan as seen from the center of the Earth over the
last four months of 2008. Model both target bodies as
ellipsoids. Search for every type of occultation.
Use light time corrections to model apparent positions of
Saturn and Titan. Stellar aberration corrections are not
specified because they don't affect occultation computations.
We select a step size of 15 minutes, which means we
ignore occultation events lasting less than 15 minutes,
if any exist.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: gfoclt_ex2.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
de421.bsp Planetary ephemeris
sat288.bsp Satellite ephemeris for
Saturn
pck00008.tpc Planet orientation and
radii
naif0009.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'de421.bsp',
'sat288.bsp',
'pck00008.tpc',
'naif0009.tls' )
\begintext
End of meta-kernel
Example code begins here.
#include <stdio.h>
#include <string.h>
#include "SpiceUsr.h"
int main()
{
/.
Local constants
./
#define TIMFMT "YYYY MON DD HR:MN:SC.###### (TDB)::TDB"
#define MAXWIN 200
#define TIMLEN 41
#define LNSIZE 81
#define NTYPES 4
/.
Local variables
./
SPICEDOUBLE_CELL ( cnfine, MAXWIN );
SPICEDOUBLE_CELL ( result, MAXWIN );
SpiceChar * back;
SpiceChar * bframe;
SpiceChar * front;
SpiceChar * fframe;
SpiceChar line [ LNSIZE ];
SpiceChar * obsrvr;
SpiceChar * occtyp [ NTYPES ] =
{
"FULL",
"ANNULAR",
"PARTIAL",
"ANY"
};
SpiceChar * templt [ NTYPES ] =
{
"Condition: # occultation of # by #",
"Condition: # occultation of # by #",
"Condition: # occultation of # by #",
"Condition: # occultation of # by #"
};
SpiceChar timstr [ TIMLEN ];
SpiceChar title [ LNSIZE ];
SpiceChar * win0;
SpiceChar * win1;
SpiceDouble et0;
SpiceDouble et1;
SpiceDouble finish;
SpiceDouble start;
SpiceDouble step;
SpiceInt i;
SpiceInt j;
SpiceInt k;
/.
Load kernels.
./
furnsh_c ( "gfoclt_ex2.tm" );
/.
Obtain the TDB time bounds of the confinement
window, which is a single interval in this case.
./
win0 = "2008 SEP 01 00:00:00 TDB";
win1 = "2009 JAN 01 00:00:00 TDB";
str2et_c ( win0, &et0 );
str2et_c ( win1, &et1 );
/.
Insert the time bounds into the confinement
window.
./
wninsd_c ( et0, et1, &cnfine );
/.
Select a 15-minute step. We'll ignore any occultations
lasting less than 15 minutes. Units are TDB seconds.
./
step = 900.0;
/.
The observation location is the Earth.
./
obsrvr = "Earth";
/.
Loop over the occultation types.
./
for ( i = 0; i < NTYPES; i++ )
{
/.
For each type, do a search for both transits of
Titan across Saturn and occultations of Titan by
Saturn.
./
for ( j = 0; j < 2; j++ )
{
if ( j == 0 )
{
front = "TITAN";
fframe = "IAU_TITAN";
back = "SATURN";
bframe = "IAU_SATURN";
}
else
{
front = "SATURN";
fframe = "IAU_SATURN";
back = "TITAN";
bframe = "IAU_TITAN";
}
/.
Perform the search. The target body shapes
are modeled as ellipsoids.
./
gfoclt_c ( occtyp[i],
front, "ellipsoid", fframe,
back, "ellipsoid", bframe,
"lt", obsrvr, step,
&cnfine, &result );
/.
Display the results.
./
printf ( "\n" );
/.
Substitute the occultation type and target
body names into the title string:
./
repmc_c ( templt[i], "#", occtyp[i], LNSIZE, title );
repmc_c ( title, "#", back, LNSIZE, title );
repmc_c ( title, "#", front, LNSIZE, title );
printf ( "%s\n", title );
if ( wncard_c(&result) == 0 )
{
printf ( " Result window is empty: "
"no occultation was found.\n" );
}
else
{
printf ( " Result window start, stop times:\n" );
for ( k = 0; k < wncard_c(&result); k++ )
{
/.
Fetch the endpoints of the kth interval
of the result window.
./
wnfetd_c ( &result, k, &start, &finish );
/.
Call strncpy with a length of 7 to include
a terminating null.
./
strncpy ( line, " # #", 7 );
timout_c ( start, TIMFMT, TIMLEN, timstr );
repmc_c ( line, "#", timstr, LNSIZE, line );
timout_c ( finish, TIMFMT, TIMLEN, timstr );
repmc_c ( line, "#", timstr, LNSIZE, line );
printf ( "%s\n", line );
}
}
/.
We've finished displaying the results of the
current search.
./
}
/.
We've finished displaying the results of the
searches using the current occultation type.
./
}
printf ( "\n" );
return ( 0 );
}
When this program was executed on a PC/Linux/gcc platform, the
output was:
Condition: FULL occultation of SATURN by TITAN
Result window is empty: no occultation was found.
Condition: FULL occultation of TITAN by SATURN
Result window start, stop times:
2008 OCT 27 22:08:01.627053 (TDB) 2008 OCT 28 01:05:03.375236 (TDB)
2008 NOV 12 21:21:59.252262 (TDB) 2008 NOV 13 02:06:05.053051 (TDB)
2008 NOV 28 20:49:02.402832 (TDB) 2008 NOV 29 02:13:58.986344 (TDB)
2008 DEC 14 20:05:09.246177 (TDB) 2008 DEC 15 01:44:53.523002 (TDB)
2008 DEC 30 19:00:56.577073 (TDB) 2008 DEC 31 00:42:43.222909 (TDB)
Condition: ANNULAR occultation of SATURN by TITAN
Result window start, stop times:
2008 OCT 19 21:29:20.599087 (TDB) 2008 OCT 19 22:53:34.518737 (TDB)
2008 NOV 04 20:15:38.620368 (TDB) 2008 NOV 05 00:18:59.139978 (TDB)
2008 NOV 20 19:38:59.647712 (TDB) 2008 NOV 21 00:35:26.725908 (TDB)
2008 DEC 06 18:58:34.073268 (TDB) 2008 DEC 07 00:16:17.647040 (TDB)
2008 DEC 22 18:02:46.288289 (TDB) 2008 DEC 22 23:26:52.712459 (TDB)
Condition: ANNULAR occultation of TITAN by SATURN
Result window is empty: no occultation was found.
Condition: PARTIAL occultation of SATURN by TITAN
Result window start, stop times:
2008 OCT 19 20:44:30.326771 (TDB) 2008 OCT 19 21:29:20.599087 (TDB)
2008 OCT 19 22:53:34.518737 (TDB) 2008 OCT 19 23:38:26.250580 (TDB)
2008 NOV 04 19:54:40.339331 (TDB) 2008 NOV 04 20:15:38.620368 (TDB)
2008 NOV 05 00:18:59.139978 (TDB) 2008 NOV 05 00:39:58.612935 (TDB)
2008 NOV 20 19:21:46.689523 (TDB) 2008 NOV 20 19:38:59.647712 (TDB)
2008 NOV 21 00:35:26.725908 (TDB) 2008 NOV 21 00:52:40.604703 (TDB)
2008 DEC 06 18:42:36.100544 (TDB) 2008 DEC 06 18:58:34.073268 (TDB)
2008 DEC 07 00:16:17.647040 (TDB) 2008 DEC 07 00:32:16.324244 (TDB)
2008 DEC 22 17:47:10.776722 (TDB) 2008 DEC 22 18:02:46.288289 (TDB)
2008 DEC 22 23:26:52.712459 (TDB) 2008 DEC 22 23:42:28.850542 (TDB)
Condition: PARTIAL occultation of TITAN by SATURN
Result window start, stop times:
2008 OCT 27 21:37:16.970175 (TDB) 2008 OCT 27 22:08:01.627053 (TDB)
2008 OCT 28 01:05:03.375236 (TDB) 2008 OCT 28 01:35:49.266506 (TDB)
2008 NOV 12 21:01:47.105498 (TDB) 2008 NOV 12 21:21:59.252262 (TDB)
2008 NOV 13 02:06:05.053051 (TDB) 2008 NOV 13 02:26:18.227357 (TDB)
2008 NOV 28 20:31:28.522707 (TDB) 2008 NOV 28 20:49:02.402832 (TDB)
2008 NOV 29 02:13:58.986344 (TDB) 2008 NOV 29 02:31:33.691598 (TDB)
2008 DEC 14 19:48:27.094229 (TDB) 2008 DEC 14 20:05:09.246177 (TDB)
2008 DEC 15 01:44:53.523002 (TDB) 2008 DEC 15 02:01:36.360243 (TDB)
2008 DEC 30 18:44:23.485898 (TDB) 2008 DEC 30 19:00:56.577073 (TDB)
2008 DEC 31 00:42:43.222909 (TDB) 2008 DEC 31 00:59:17.030568 (TDB)
Condition: ANY occultation of SATURN by TITAN
Result window start, stop times:
2008 OCT 19 20:44:30.326771 (TDB) 2008 OCT 19 23:38:26.250580 (TDB)
2008 NOV 04 19:54:40.339331 (TDB) 2008 NOV 05 00:39:58.612935 (TDB)
2008 NOV 20 19:21:46.689523 (TDB) 2008 NOV 21 00:52:40.604703 (TDB)
2008 DEC 06 18:42:36.100544 (TDB) 2008 DEC 07 00:32:16.324244 (TDB)
2008 DEC 22 17:47:10.776722 (TDB) 2008 DEC 22 23:42:28.850542 (TDB)
Condition: ANY occultation of TITAN by SATURN
Result window start, stop times:
2008 OCT 27 21:37:16.970175 (TDB) 2008 OCT 28 01:35:49.266506 (TDB)
2008 NOV 12 21:01:47.105498 (TDB) 2008 NOV 13 02:26:18.227357 (TDB)
2008 NOV 28 20:31:28.522707 (TDB) 2008 NOV 29 02:31:33.691598 (TDB)
2008 DEC 14 19:48:27.094229 (TDB) 2008 DEC 15 02:01:36.360243 (TDB)
2008 DEC 30 18:44:23.485898 (TDB) 2008 DEC 31 00:59:17.030568 (TDB)
-Restrictions
The kernel files to be used by gfoclt_c must be loaded (normally via
the CSPICE routine furnsh_c) before gfoclt_c is called.
-Literature_References
None.
-Author_and_Institution
N. J. Bachman (JPL)
L. S. Elson (JPL)
E. D. Wright (JPL)
-Version
-CSPICE Version 1.0.0, 07-APR-2009 (NJB) (LSE) (EDW)
-Index_Entries
GF occultation search
-&
*/
{ /* Begin gfoclt_c */
/*
Local variables
*/
static const SpiceChar * blankStr = " ";
SpiceChar * bFrameStr;
SpiceChar * fFrameStr;
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "gfoclt_c" );
/*
Make sure cell data types are d.p.
*/
CELLTYPECHK2 ( CHK_STANDARD, "gfoclt_c", SPICE_DP, cnfine, result );
/*
Initialize the input cells if necessary.
*/
CELLINIT2 ( cnfine, result );
/*
The input frame names are special cases because we allow the caller
to pass in empty strings. If either of these strings are empty,
we pass a null-terminated string containing one blank character to
the underlying f2c'd routine.
First make sure the frame name pointers are non-null.
*/
CHKPTR ( CHK_STANDARD, "gfoclt_c", bframe );
CHKPTR ( CHK_STANDARD, "gfoclt_c", fframe );
/*
Use the input frame strings if they're non-empty; otherwise
use blank strings for the frame names.
*/
if ( bframe[0] )
{
bFrameStr = (SpiceChar *) bframe;
}
else
{
bFrameStr = (SpiceChar *) blankStr;
}
if ( fframe[0] )
{
fFrameStr = (SpiceChar *) fframe;
}
else
{
fFrameStr = (SpiceChar *) blankStr;
}
/*
Check the other input strings to make sure each pointer is non-null
and each string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "gfoclt_c", occtyp );
CHKFSTR ( CHK_STANDARD, "gfoclt_c", front );
CHKFSTR ( CHK_STANDARD, "gfoclt_c", fshape );
CHKFSTR ( CHK_STANDARD, "gfoclt_c", back );
CHKFSTR ( CHK_STANDARD, "gfoclt_c", bshape );
CHKFSTR ( CHK_STANDARD, "gfoclt_c", abcorr );
CHKFSTR ( CHK_STANDARD, "gfoclt_c", obsrvr );
/*
Let the f2c'd routine do the work.
*/
gfoclt_ ( (char *) occtyp,
(char *) front,
(char *) fshape,
(char *) fFrameStr,
(char *) back,
(char *) bshape,
(char *) bFrameStr,
(char *) abcorr,
(char *) obsrvr,
(doublereal *) &step,
(doublereal *) cnfine->base,
(doublereal *) result->base,
(ftnlen ) strlen(occtyp),
(ftnlen ) strlen(front),
(ftnlen ) strlen(fshape),
(ftnlen ) strlen(fframe),
(ftnlen ) strlen(back),
(ftnlen ) strlen(bshape),
(ftnlen ) strlen(bframe),
(ftnlen ) strlen(abcorr),
(ftnlen ) strlen(obsrvr) );
/*
Sync the output result cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, result );
}
chkout_c ( "gfoclt_c" );
} /* End gfoclt_c */
void pckcov_c ( ConstSpiceChar * pck,
SpiceInt idcode,
SpiceCell * cover )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
pck I Name of PCK file.
idcode I Class ID code of PCK reference frame.
cover I/O Window giving coverage in `pck' for `idcode'.
-Detailed_Input
pck is the name of a binary PCK file.
idcode is the integer frame class ID code of a PCK reference
frame for which data are expected to exist in the
specified PCK file.
cover is an initialized CSPICE window data structure.
`cover' optionally may contain coverage data on
input; on output, the data already present in `cover'
will be combined with coverage found for the
reference frame designated by `idcode' in the file
`pck'.
If `cover' contains no data on input, its size and
cardinality still must be initialized.
-Detailed_Output
cover is a CSPICE window data structure which represents
the merged coverage for the reference frame having
frame class ID `idcode'. This is the set of time
intervals for which data for `idcode' are present in
the file `pck', merged with the set of time intervals
present in `cover' on input. The merged coverage is
represented as the union of one or more disjoint time
intervals. The window `cover' contains the pairs of
endpoints of these intervals.
The interval endpoints contained in `cover' are
ephemeris times, expressed as seconds past J2000
TDB.
See the Examples section below for a complete
example program showing how to retrieve the
endpoints from `cover'.
-Parameters
None.
-Exceptions
1) If the input file has transfer format, the error
SPICE(INVALIDFORMAT) is signaled.
2) If the input file is not a transfer file but has architecture
other than DAF, the error SPICE(BADARCHTYPE) is signaled.
3) If the input file is a binary DAF file of type other than
PCK, the error SPICE(BADFILETYPE) is signaled.
4) If the PCK file cannot be opened or read, the error will
be diagnosed by routines called by this routine. The output
window will not be modified.
5) If the size of the output window argument COVER is
insufficient to contain the actual number of intervals in the
coverage window for IDCODE, the error will be diagnosed by
routines called by this routine.
6) The error SPICE(EMPTYSTRING) is signaled if the input
string `pck' does not contain at least one character, since the
input string cannot be converted to a Fortran-style string in
this case.
7) The error SPICE(NULLPOINTER) is signaled if the input string
pointer `pck' is null.
-Files
This routine reads a PCK file.
-Particulars
This routine provides an API via which applications can determine
the coverage a specified PCK file provides for a specified
PCK class reference frame.
-Examples
1) This example demonstrates combined usage of pckcov_c and the
related PCK utility pckfrm_c.
Display the coverage for each object in a specified PCK file.
Find the set of objects in the file; for each object, find
and display the coverage.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local parameters
./
#define FILSIZ 256
#define MAXIV 1000
#define WINSIZ ( 2 * MAXIV )
#define TIMLEN 51
#define MAXOBJ 1000
/.
Local variables
./
SPICEDOUBLE_CELL ( cover, WINSIZ );
SPICEINT_CELL ( ids, MAXOBJ );
SpiceChar lsk [ FILSIZ ];
SpiceChar pck [ FILSIZ ];
SpiceChar timstr [ TIMLEN ];
SpiceDouble b;
SpiceDouble e;
SpiceInt i;
SpiceInt j;
SpiceInt niv;
SpiceInt obj;
/.
Load a leapseconds kernel for output time conversion.
PCKCOV itself does not require a leapseconds kernel.
./
prompt_c ( "Name of leapseconds kernel > ", FILSIZ, lsk );
furnsh_c ( lsk );
/.
Get name of PCK file.
./
prompt_c ( "Name of PCK file > ", FILSIZ, pck );
/.
Find the set of frames in the PCK file.
./
pckfrm_c ( pck, &ids );
/.
We want to display the coverage for each frame. Loop over
the contents of the ID code set, find the coverage for
each item in the set, and display the coverage.
./
for ( i = 0; i < card_c( &ids ); i++ )
{
/.
Find the coverage window for the current frame.
Empty the coverage window each time so we don't
include data for the previous frame.
./
obj = SPICE_CELL_ELEM_I( &ids, i );
scard_c ( 0, &cover );
pckcov_c ( pck, obj, &cover );
/.
Get the number of intervals in the coverage window.
./
niv = wncard_c ( &cover );
/.
Display a simple banner.
./
printf ( "%s\n", "========================================" );
printf ( "Coverage for frame %ld\n", obj );
/.
Convert the coverage interval start and stop times to TDB
calendar strings.
./
for ( j = 0; j < niv; j++ )
{
/.
Get the endpoints of the jth interval.
./
wnfetd_c ( &cover, j, &b, &e );
/.
Convert the endpoints to TDB calendar
format time strings and display them.
./
timout_c ( b,
"YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "\n"
"Interval: %ld\n"
"Start: %s\n",
j,
timstr );
timout_c ( e,
"YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "Stop: %s\n", timstr );
}
}
return ( 0 );
}
2) Find the coverage for the frame designated by `idcode'
provided by the set of PCK files loaded via a metakernel.
(The metakernel must also specify a leapseconds kernel.)
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local parameters
./
#define FILSIZ 256
#define LNSIZE 81
#define MAXCOV 100000
#define WINSIZ ( 2 * MAXCOV )
#define TIMLEN 51
/.
Local variables
./
SPICEDOUBLE_CELL ( cover, WINSIZ );
SpiceBoolean found;
SpiceChar file [ FILSIZ ];
SpiceChar idch [ LNSIZE ];
SpiceChar meta [ FILSIZ ];
SpiceChar source [ FILSIZ ];
SpiceChar timstr [ TIMLEN ];
SpiceChar type [ LNSIZE ];
SpiceDouble b;
SpiceDouble e;
SpiceInt count;
SpiceInt handle;
SpiceInt i;
SpiceInt idcode;
SpiceInt niv;
/.
Prompt for the metakernel name; load the metakernel.
The metakernel lists the PCK files whose coverage
for `idcode' we'd like to determine. The metakernel
must also specify a leapseconds kernel.
./
prompt_c ( "Name of metakernel > ", FILSIZ, meta );
furnsh_c ( meta );
/.
Get the ID code of interest.
./
prompt_c ( "Enter ID code > ", LNSIZE, idch );
prsint_c ( idch, &idcode );
/.
Find out how many kernels are loaded. Loop over the
kernels: for each loaded PCK file, add its coverage
for `idcode', if any, to the coverage window.
./
ktotal_c ( "PCK", &count );
for ( i = 0; i < count; i++ )
{
kdata_c ( i, "PCK", FILSIZ, LNSIZE, FILSIZ,
file, type, source, &handle, &found );
pckcov_c ( file, idcode, &cover );
}
/.
Display results.
Get the number of intervals in the coverage window.
./
niv = wncard_c ( &cover );
/.
Display a simple banner.
./
printf ( "\nCoverage for frame %ld\n", idcode );
/.
Convert the coverage interval start and stop times to TDB
calendar strings.
./
for ( i = 0; i < niv; i++ )
{
/.
Get the endpoints of the ith interval.
./
wnfetd_c ( &cover, i, &b, &e );
/.
Convert the endpoints to TDB calendar
format time strings and display them.
./
timout_c ( b,
"YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "\n"
"Interval: %ld\n"
"Start: %s\n",
i,
timstr );
timout_c ( e,
"YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "Stop: %s\n", timstr );
}
return ( 0 );
}
-Restrictions
1) If an error occurs while this routine is updating the window
`cover', the window may be corrupted.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.0.1, 01-JUL-2014 (NJB)
Updated index entries.
-CSPICE Version 1.0.0, 30-NOV-2007 (NJB)
-Index_Entries
get coverage window for binary pck reference frame
get coverage start and stop time for binary pck frame
-&
*/
{ /* Begin pckcov_c */
/*
Participate in error tracing.
*/
if ( return_c() )
{
return;
}
chkin_c ( "pckcov_c" );
/*
Check the input string `pck' to make sure the pointer is non-null
and the string length is non-zero.
*/
CHKFSTR ( CHK_STANDARD, "pckcov_c", pck );
/*
Make sure cell data type is d.p.
*/
CELLTYPECHK ( CHK_STANDARD, "pckcov_c", SPICE_DP, cover );
/*
Initialize the cell if necessary.
*/
CELLINIT ( cover );
/*
Call the f2c'd Fortran routine.
*/
pckcov_ ( ( char * ) pck,
( integer * ) &idcode,
( doublereal * ) (cover->base),
( ftnlen ) strlen(pck) );
/*
Sync the output cell.
*/
if ( !failed_c() )
{
zzsynccl_c ( F2C, cover );
}
chkout_c ( "pckcov_c" );
} /* End pckcov_c */
//function to load new data into the body
void body::load_body_data(const int& ibody_code, const string& iname, const string& ishortname, const int& ispice_ID, const double& imininum_altitude, const double& imass, const double& iradius, const double& iepoch, vector<double>& ireference_angles, vector<double>& iclassical_orbit_elements, const double& iuniverse_mu, const int& icentral_body_SPICE_ID, const string& icentral_body_name, const double& icentral_body_radius, missionoptions* options)
{
//copy information from the inputs into the body
this->name = iname;
this->short_name = ishortname;
this->universe_mu = iuniverse_mu;
this->body_code = ibody_code;
this->central_body_spice_ID = icentral_body_SPICE_ID;
this->central_body_name = icentral_body_name;
this->central_body_radius = icentral_body_radius;
this->spice_ID = ispice_ID;
this->minimum_safe_flyby_altitude = imininum_altitude;
this->mass = imass;
this->radius = iradius;
this->reference_epoch = iepoch;
this->SMA = iclassical_orbit_elements[0];
this->ECC = iclassical_orbit_elements[1];
this->INC = iclassical_orbit_elements[2] * EMTG::math::PI / 180.0;
this->RAAN = iclassical_orbit_elements[3] * EMTG::math::PI / 180.0;
this->AOP = iclassical_orbit_elements[4] * EMTG::math::PI / 180.0;
this->MA = iclassical_orbit_elements[5] * EMTG::math::PI / 180.0;
//compute additional values
mu = options->G * mass;
if (ECC < 0.2)
r_SOI = SMA * pow(mu / universe_mu, 0.4);
else
r_SOI = SMA * (1 - ECC) * pow(mu / (3.0 * universe_mu), 0.333333333333333333333333);
//determine which ephemeris to draw from
if (options->ephemeris_source == 0)
{
body_ephemeris_source = 0; //use static ephemeris
ephemeris_start_date = -0;
ephemeris_end_date = 1e+10;
}
else if (options->ephemeris_source == 1)
{
//first, check to see if the body exists in the currently loaded SPICE kernels
double temp_state[6];
double LT_dump;
spkez_c (spice_ID, reference_epoch - (51544.5 * 86400.0), "J2000", "NONE", central_body_spice_ID, temp_state, <_dump);
if (failed_c())
reset_c();
if (fabs(temp_state[0]) > 1.0e-6 && fabs(temp_state[0]) < 1.0e+50)
{
body_ephemeris_source = 1; //body can be located using SPICE
}
else
{
cout << "Warning, body " << name << " does not have a SPICE ephemeris file." << endl;
body_ephemeris_source = 0; //use static ephemeris
ephemeris_start_date = 0;
ephemeris_end_date = 1e+10;
}
}
J2000_body_equatorial_frame.initialize(ireference_angles[0], ireference_angles[1], ireference_angles[2], ireference_angles[3], ireference_angles[4], ireference_angles[5]);
}