void mtxv_c ( ConstSpiceDouble m1 [3][3],
ConstSpiceDouble vin [3],
SpiceDouble vout[3] )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
m1 I 3x3 double precision matrix.
vin I 3-dimensional double precision vector.
vout O 3-dimensional double precision vector. vout is
the product m1**t * vin.
-Detailed_Input
m1 is an arbitrary 3x3 double precision matrix.
typically, m1 will be a rotation matrix since
then its transpose is its inverse (but this is NOT
a requirement).
vin is an arbitrary 3-dimensional double precision
vector.
-Detailed_Output
vout is a 3-dimensional double precision vector. vout is
the product vout = (m1**t) x (vin). vout can
overwrite vin.
-Parameters
None.
-Particulars
The intermediate results of the operation performed by this routine
are buffered in a temporary vector which is later moved to the output
vector. Thus vout can be actually vin if desired without
interfering with the computation.
-Examples
Typically the matrix m1 will be a rotation matrix. Because
the transpose of an orthogonal matrix is equivalent to its
inverse, applying the rotation to the vector is accomplished by
multiplying the vector by the transpose of the matrix.
-1
let m1 * vin = vout. If m1 is an orthogonal matrix,
then (m1**t) * vin = vout.
If m1 = | 1. 1. 0. | and vin = | 5. |
| | | |
| -1. 1. 0. | | 10. |
| | | |
| 0. 0. 1. | | 15. |
then the call
mtxv_c ( m1, vin, vout )
produces the vector
vout = | -5. |
| |
| 15. |
| |
| 15. |
-Restrictions
The user is responsible for checking the magnitudes of the
elements of m1 and vin so that a floating point overflow does
not occur.
-Exceptions
Error free.
-Files
None.
-Author_and_Institution
E.D. Wright (JPL)
W.M. Owen (JPL)
-Literature_References
None.
-Version
-CSPICE Version 1.0.1, 10-NOV-2006 (EDW)
Added Parameters section header.
-CSPICE Version 1.0.0, 16-APR-1999 (EDW)
-Index_Entries
matrix_transpose times 3-dimensional vector
-&
*/
{ /* Begin mtxv_c */
/*
Local variables
*/
SpiceInt i;
SpiceDouble vtemp[3];
for ( i = 0; i <= 2; i++ )
{
vtemp[i] = m1[0][i]*vin[0] + m1[1][i]*vin[1] + m1[2][i]*vin[2];
}
/* Move the computed result to the output array. */
MOVED ( vtemp, 3, vout );
} /* End mtxv_c */
void xpose6_c ( ConstSpiceDouble m1[6][6], SpiceDouble mout[6][6] )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
m1 I 6x6 matrix to be transposed.
mout O Transpose of m1. mout can overwrite m1.
-Detailed_Input
m1 This variable may contain any double precision 6x6
matrix.
-Detailed_Output
mout This variable is a double precision, 6x6 matrix which
contains the transpose of m1. mout may overwrite m1.
-Parameters
None.
-Exceptions
Error free.
-Files
None.
-Particulars
This is a utility routine intended to facilitate passing state
transformation matrices between C and Fortan.
-Examples
Given below is one example of a matrix m1 with the output matrix
mout which is implied by m1.
| 1 2 3 4 5 6 | | 1 0 0 0 0 0 |
| 0 7 8 9 10 11 | | 2 7 0 0 0 0 |
| 0 0 12 13 14 15 | | 3 8 12 0 0 0 |
m1= | 0 0 0 16 17 18 | then mout = | 4 9 13 16 0 0 |
| 0 0 0 0 19 20 | | 5 10 14 17 19 0 |
| 0 0 0 0 0 21 | | 6 11 15 18 20 21|
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
W.L. Taber (JPL)
W.M. Owen (JPL)
-Version
-CSPICE Version 1.0.3, 08-JAN-2014 (BVS)
Corrected a minor typo in the header.
-CSPICE Version 1.0.2, 16-JAN-2008 (EDW)
Corrected typos in header titles:
Detailed Input to Detailed_Input
Detailed Output to Detailed_Output
-CSPICE Version 1.0.1, 10-NOV-2006 (EDW)
Added Keywords and Parameters section headers.
Reordered section headers.
-CSPICE Version 1.0.0, 16-APR-1999 (NJB)
-Index_Entries
transpose a 6x6_matrix
-&
*/
{ /* Begin xpose6_c */
/*
Local constants
*/
#define SIZE 6
#define SIZESQ 36
/*
Local variables
*/
SpiceInt col;
SpiceInt row;
SpiceDouble temp[SIZE][SIZE];
/*
Capture a temporary copy of the input matrix.
*/
MOVED ( m1, SIZESQ, temp );
/*
Move the temporary matrix to the output matrix, transposing as
we go.
*/
for ( row = 0; row < SIZE; row++ )
{
for ( col = 0; col < SIZE; col++ )
{
mout[row][col] = temp[col][row];
}
}
} /* End xpose6_c */
void pl2nvc_c ( ConstSpicePlane * plane,
SpiceDouble normal[3],
SpiceDouble * constant )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
plane I A CSPICE plane.
normal,
constant O A normal vector and constant defining the
geometric plane represented by plane.
-Detailed_Input
plane is a CSPICE plane.
-Detailed_Output
normal,
constant are, respectively, a unit normal vector and
constant that define the geometric plane
represented by plane. Let the symbol < a, b >
indicate the inner product of vectors a and b;
then the geometric plane is the set of vectors x
in three-dimensional space that satisfy
< x, normal > = constant.
normal is a unit vector. constant is the distance of
the plane from the origin;
constant * normal
is the closest point in the plane to the origin.
-Parameters
None.
-Exceptions
Error free.
1) The input plane MUST have been created by one of the CSPICE
routines
nvc2pl_c ( Normal vector and constant to plane )
nvp2pl_c ( Normal vector and point to plane )
psv2pl_c ( Point and spanning vectors to plane )
Otherwise, the results of this routine are unpredictable.
-Files
None.
-Particulars
CSPICE geometry routines that deal with planes use the `plane'
data type to represent input and output planes. This data type
makes the subroutine interfaces simpler and more uniform.
The CSPICE routines that produce CSPICE planes from data that
define a plane are:
nvc2pl_c ( Normal vector and constant to plane )
nvp2pl_c ( Normal vector and point to plane )
psv2pl_c ( Point and spanning vectors to plane )
The CSPICE routines that convert CSPICE planes to data that
define a plane are:
pl2nvc_c ( Plane to normal vector and constant )
pl2nvp_c ( Plane to normal vector and point )
pl2psv_c ( Plane to point and spanning vectors )
-Examples
1) Given a point in a plane and a normal vector, find the distance
of the plane from the origin. We make a `plane' from the point
and normal, then convert the plane to a unit normal and constant.
The constant is the distance of the plane from the origin.
nvp2pl_c ( normal, point, &plane );
pl2nvc_c ( &plane, normal, &constant );
2) Apply a linear transformation represented by the matrix m to
a plane represented by the normal vector n and the constant c.
Find a normal vector and constant for the transformed plane.
/.
Make a CSPICE plane from n and c, and then find a
point in the plane and spanning vectors for the
plane. n need not be a unit vector.
./
nvc2pl_c ( n, c, &plane );
pl2psv_c ( &plane, point, span1, span2 );
/.
Apply the linear transformation to the point and
spanning vectors. All we need to do is multiply
these vectors by m, since for any linear
transformation T,
T ( point + t1 * span1 + t2 * span2 )
= T (point) + t1 * T(span1) + t2 * T(span2),
which means that T(point), T(span1), and T(span2)
are a point and spanning vectors for the transformed
plane.
./
mxv_c ( m, point, tpoint );
mxv_c ( m, span1, tspan1 );
mxv_c ( m, span2, tspan2 );
/.
Make a new CSPICE plane tplane from the
transformed point and spanning vectors, and find a
unit normal and constant for this new plane.
./
psv2pl_c ( tpoint, tspan1, tspan2, &tplane );
pl2nvc_c ( &tplane, tn, &tc );
-Restrictions
None.
-Literature_References
[1] `Calculus and Analytic Geometry', Thomas and Finney.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.0.1, 06-FEB-2003 (EDW)
Trivial correction to header docs.
-CSPICE Version 1.0.0, 05-MAR-1999 (NJB)
-Index_Entries
plane to normal vector and constant
-&
*/
{ /* Begin pl2nvc_c */
/*
Unpack the plane.
*/
MOVED ( plane->normal, 3, normal );
*constant = plane->constant;
} /* End pl2nvc_c */
void vcrss_c ( ConstSpiceDouble v1[3],
ConstSpiceDouble v2[3],
SpiceDouble vout[3] )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
v1 I Left hand vector for cross product.
v2 I Right hand vector for cross product.
vout O Cross product v1xv2.
vout can overwrite either v1 or v2.
-Detailed_Input
v1 This may be any 3-dimensional vector. Typically, this
might represent the (possibly unit) vector to a planet,
sun, or a star which defines the orientation of axes of
some coordinate system.
v2 Ditto.
-Detailed_Output
vout This variable represents the cross product of v1 and v2.
vout may overwrite v1 or v2.
-Parameters
None.
-Particulars
vcrss_c calculates the three dimensional cross product of two
vectors according to the definition. The cross product is stored
in a buffer vector until the calculation is complete. Thus vout
may overwrite v1 or v2 without interfering with intermediate
computations.
If v1 and v2 are large in magnitude (taken together, their
magnitude surpasses the limit allow by the computer) then it may
be possible to generate a floating point overflow from an
intermediate computation even though the actual cross product
may be well within the range of double precision numbers.
vcrss_c does NOT check the magnitude of v1 or v2 to insure that
overflow will not occur.
-Examples
v1 v2 vout (=v1Xv2)
-----------------------------------------------------------------
(0, 1, 0) (1, 0, 0) (0, 0, -1)
(5, 5, 5) (-1, -1, -1) (0, 0, 0)
-Restrictions
No checking of v1 or v2 is done to prevent floating point
overflow. The user is required to determine that the magnitude
of each component of the vectors is within an appropriate range
so as not to cause floating point overflow. In almost every case
there will be no problem and no checking actually needs to be
done.
-Exceptions
Error free.
-Files
None.
-Author_and_Institution
W.M. Owen (JPL)
E.D. Wright (JPL)
-Literature_References
None.
-Version
-CSPICE Version 1.1.0, 22-OCT-1998 (NJB)
Made input vectors const.
-CSPICE Version 1.0.1, 06-MAR-1998 (EDW)
Minor header correction. Added use of MOVED.
-CSPICE Version 1.0.0, 08-FEB-1998 (EDW)
-Index_Entries
vector cross product
-&
*/
{ /* Begin vcrss_c */
/*
Local variables
*/
SpiceDouble vtemp[3];
/*
Calculate the cross product of v1 and v2, store in vtemp.
*/
vtemp[0] = v1[1]*v2[2] - v1[2]*v2[1];
vtemp[1] = v1[2]*v2[0] - v1[0]*v2[2];
vtemp[2] = v1[0]*v2[1] - v1[1]*v2[0];
/*
Now move the result into vout.
*/
MOVED ( vtemp, 3, vout );
} /* End vcrss_c */
void el2cgv_c ( ConstSpiceEllipse * ellipse,
SpiceDouble center[3],
SpiceDouble smajor[3],
SpiceDouble sminor[3] )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
ellipse I A CSPICE ellipse.
center,
smajor,
sminor O Center and semi-axes of ellipse.
-Detailed_Input
ellipse is a CSPICE ellipse.
-Detailed_Output
center,
smajor,
sminor are, respectively, a center vector, a semi-major
axis vector, and a semi-minor axis vector that
generate the input ellipse. This ellipse is the
set of points
center + cos(theta) smajor + sin(theta) sminor
where theta ranges over the interval (-pi, pi].
-Parameters
None.
-Exceptions
Error free.
-Files
None.
-Particulars
CSPICE ellipses serve to simplify calling sequences and reduce
the chance for error in declaring and describing argument lists
involving ellipses.
The set of ellipse conversion routines is
cgv2el_c ( Center and generating vectors to ellipse )
el2cgv_c ( Ellipse to center and generating vectors )
A word about the output of this routine: the semi-major axis of
an ellipse is a vector of largest possible magnitude in the set
cos(theta) vec1 + sin(theta) vec2,
where theta is in the interval (-pi, pi]. There are two such
vectors; they are additive inverses of each other. The semi-minor
axis is an analogous vector of smallest possible magnitude. The
semi-major and semi-minor axes are orthogonal to each other. If
smajor and sminor are choices of semi-major and semi-minor axes,
then the input ellipse can also be represented as the set of
points
center + cos(theta) smajor + sin(theta) sminor
where theta ranges over the interval (-pi, pi].
-Examples
1) Find the semi-axes of the limb of an ellipsoid.
#include "SpiceUsr.h"
.
.
.
/.
Our viewing location is viewpt. The radii of the
ellipsoid are a, b, and c.
./
edlimb_c ( a, b, c, viewpt, &limb );
el2cgv_c ( &limb, center, smajor, sminor );
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.0.0, 12-JUN-1999 (NJB)
-Index_Entries
ellipse to center and generating vectors
-&
*/
{ /* Begin el2cgv_c */
/*
Error free.
*/
MOVED ( ellipse->center, 3, center );
MOVED ( ellipse->semiMajor, 3, smajor );
MOVED ( ellipse->semiMinor, 3, sminor );
} /* End el2cgv_c */
void mxmg_c ( const void * m1,
const void * m2,
SpiceInt nrow1,
SpiceInt ncol1,
SpiceInt ncol2,
void * mout )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
m1 I nrow1 X ncol1 double precision matrix.
m2 I ncol1 X ncol2 double precision matrix.
nrow1 I Row dimension of m1 (and also mout).
ncol1 I Column dimension of m1 and row dimension of m2.
ncol2 I Column dimension of m2 (and also mout).
mout O nrow1 X ncol2 double precision matrix.
-Detailed_Input
m1 is any double precision matrix of arbitrary size.
m2 is any double precision matrix of arbitrary size.
The number of rows in m2 must match the number of
columns in m1.
nrow1 is the number of rows in both m1 and mout.
ncol1 is the number of columns in m1 and (by necessity)
the number of rows of m2.
ncol2 is the number of columns in both m2 and mout.
-Detailed_Output
mout
mout is the product matrix defined by
mout = (m1) x (m2)
mout is a double precision matrix of dimension nrow1 x
ncol2.
mout may overwrite m1 or m2. Note that this capability
does not exist in the Fortran version of SPICELIB; in the
Fortran version, the output must not overwrite either
input.
-Parameters
None.
-Exceptions
1) If dynamic allocation of memory fails, the error
SPICE(MEMALLOCFAILED) is signalled.
-Files
None.
-Particulars
The code reflects precisely the following mathematical expression
For each value of the subscript i from 1 to nrow1, and j from 1
to ncol2:
mout(i,j) = Summation from k=1 to ncol1 of m1(i,k) * m2(k,j)
-Examples
Let
m1 = | 1.0 4.0 | and m2 = | 1.0 3.0 5.0 |
| | |
| 2.0 5.0 | | 2.0 4.0 6.0 |
| |
| 3.0 6.0 |
and
nrow1 = 3
ncol1 = 2
ncol2 = 3
Then the call
mxmg ( m1, m2, nrow1, ncol1, ncol2, mout );
produces the matrix
mout = | 9.0 19.0 29.0 |
| |
| 12.0 26.0 40.0 |
| |
| 15.0 33.0 51.0 |
-Restrictions
1) No error checking is performed to prevent numeric overflow or
underflow.
2) No error checking performed to determine if the input and
output matrices have, in fact, been correctly dimensioned.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
W.M. Owen (JPL)
-Version
-CSPICE Version 1.1.2, 16-JAN-2008 (EDW)
Corrected typos in header titles:
Detailed Input to Detailed_Input
Detailed Output to Detailed_Output
-CSPICE Version 1.1.1, 10-NOV-2006 (EDW)
Added Parameters section header.
-CSPICE Version 1.1.0, 28-AUG-2001 (NJB)
Const-qualified input arrays.
-CSPICE Version 1.0.0, 16-APR-1999 (NJB)
-Index_Entries
matrix times matrix n-dimensional_case
-&
*/
{ /* Begin mxmg_c */
/*
Local macros
We'd like to be able to refer to the elements of the input and output
matrices using normal subscripts, for example, m1[2][3]. Since the
compiler doesn't know how to compute index offsets for the array
arguments, which have user-adjustable size, we must compute the
offsets ourselves. To make syntax a little easier to read (we hope),
we'll use macros to do the computations.
The macro INDEX(width, i,j) computes the index offset from the array
base of the element at position [i][j] in a 2-dimensional matrix
having the number of columns indicated by width. For example, if
the input matrix m1 has 2 rows and 3 columns, the element at position
[0][1] would be indicated by
m1[ INDEX(3,0,1) ]
*/
#define INDEX( width, row, col ) ( (row)*(width) + (col) )
/*
Local variables
*/
SpiceDouble innerProduct;
SpiceDouble *tmpmat;
SpiceDouble *loc_m1;
SpiceDouble *loc_m2;
SpiceInt col;
SpiceInt nelts;
SpiceInt row;
SpiceInt i;
size_t size;
/*
Allocate space for a temporary copy of the output matrix, which
has nrow1 rows and ncol2 columns.
*/
nelts = nrow1 * ncol2;
size = (size_t) ( nelts * sizeof(SpiceDouble) );
tmpmat = (SpiceDouble *) malloc ( size );
if ( tmpmat == (SpiceDouble *)0 )
{
chkin_c ( "mxmg_c" );
setmsg_c ( "An attempt to create a temporary matrix failed." );
sigerr_c ( "SPICE(MEMALLOCFAILED)" );
chkout_c ( "mxmg_c" );
return;
}
/*
Cast the input pointers to pointers to SpiceDoubles. Note: the
original variables are pointers to void so that callers may
supply the array names as arguments without casting them to
SpiceDoubles. The naked array name is considered by the compiler
to be an incompatible pointer type with (SpiceDouble *), so we
can't simply declare the arguments to be (SpiceDouble *). On the
other hand, every pointer type can be cast to (void *).
*/
loc_m1 = (SpiceDouble *) m1;
loc_m2 = (SpiceDouble *) m2;
/*
Compute the product. The matrix element at position (row,col) is
the inner product of the row of m1 having index row and the
column of m2 having index col. We compute index offsets using
the macro INDEX.
*/
for ( row = 0; row < nrow1; row++ )
{
for ( col = 0; col < ncol2; col++ )
{
innerProduct = 0.0;
for ( i = 0; i < ncol1; i++ )
{
innerProduct += loc_m1[ INDEX(ncol1, row, i ) ]
* loc_m2[ INDEX(ncol2, i, col) ];
}
tmpmat [ INDEX( ncol2, row, col ) ] = innerProduct;
}
}
/*
Move the result from tmpmat into mout.
*/
MOVED ( tmpmat, nelts, mout );
/*
Free the temporary matrix.
*/
free ( tmpmat );
} /* End mxmg_c */
void cgv2el_c ( ConstSpiceDouble center[3],
ConstSpiceDouble vec1 [3],
ConstSpiceDouble vec2 [3],
SpiceEllipse * ellipse )
/*
-Brief_I/O
Variable I/O Description
-------- --- --------------------------------------------------
center,
vec1,
vec2 I Center and two generating vectors for an ellipse.
ellipse O The CSPICE ellipse defined by the input vectors.
-Detailed_Input
center,
vec1,
vec2 are a center and two generating vectors defining
an ellipse in three-dimensional space. The
ellipse is the set of points
center + cos(theta) vec1 + sin(theta) vec2
where theta ranges over the interval (-pi, pi].
vec1 and vec2 need not be linearly independent.
-Detailed_Output
ellipse is the CSPICE ellipse defined by the input
vectors.
-Parameters
None.
-Exceptions
1) If vec1 and vec2 are linearly dependent, ellips will be
degenerate. CSPICE ellipses are allowed to represent
degenerate geometric ellipses.
-Files
None.
-Particulars
CSPICE ellipses serve to simplify calling sequences and reduce
the chance for error in declaring and describing argument lists
involving ellipses.
The set of ellipse conversion routines is
cgv2el_c ( Center and generating vectors to ellipse )
el2cgv_c ( Ellipse to center and generating vectors )
-Examples
1) Find the intersecton of an ellipse with a plane. The ellipse
is defined by the vectors center, vec1, and vec2. The plane
is defined by the normal vector n and the constant c.
#include "SpiceUsr.h"
.
.
.
/.
Make a CSPICE ellipse. Make a plane while we're at it.
./
cgv2el_c ( center, vec1, vec2, &ellipse );
nvc2pl_c ( n, c, &plane );
/.
Find the intersection of the ellipse and plane.
nxpts is the number of intersection points; xpt1
and xpt2 are the points themselves.
./
inelpl_c ( &ellipse, &plane, &nxpts, xpt1, xpt2 );
-Restrictions
None.
-Literature_References
None.
-Author_and_Institution
N.J. Bachman (JPL)
-Version
-CSPICE Version 1.0.0, 05-MAR-1999 (NJB)
-Index_Entries
center and generating vectors to ellipse
-&
*/
{ /* Begin cgv2el_c */
/*
Participate in error tracing.
*/
chkin_c ( "cgv2el_c" );
/*
The center of the ellipse is held in the first three elements.
*/
MOVED ( center, 3, ellipse->center );
/*
Find the semi-axes of the ellipse. These may be degenerate.
*/
saelgv_c ( vec1, vec2, ellipse->semiMajor, ellipse->semiMinor );
chkout_c ( "cgv2el_c" );
} /* End cgv2el_c */
void mtxm_c ( ConstSpiceDouble m1 [3][3],
ConstSpiceDouble m2 [3][3],
SpiceDouble mout[3][3] )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
m1 I 3x3 double precision matrix.
m2 I 3x3 double precision matrix.
mout O The produce m1 transpose times m2.
-Detailed_Input
m1 is any 3x3 double precision matrix. Typically,
m1 will be a rotation matrix since then its
transpose is its inverse (but this is not a
requirement).
m2 is any 3x3 double precision matrix.
-Detailed_Output
mout is a 3x3 double precision matrix. mout is the
product
t
mout = m1 m2
mout may overwrite either m1 or m2.
-Parameters
None.
-Particulars
The code reflects precisely the following mathematical expression
For each value of the subscripts i and j from 0 to 2:
2
__
\
mout[i][j] = /_ m1[k][i] * m2[k][j]
k=0
Note that the reversal of the k and i subscripts in the left-hand
matrix m1 is what makes mout the product of the TRANSPOSE of M1
and not simply of m1 itself. Also, the intermediate results of
the operation above are buffered in a temporary matrix which is
later moved to the output matrix. Thus mout can be actually be
m1 or m2 if desired without interfering with the computations.
-Examples
Let m1 = | 1. 2. 3. |
| |
| 4. 5. 6. |
| |
| 7. 8. 9. |
m2 = | 1. 1. 0. |
| |
| -1. 1. 0. |
| |
| 0. 0. 1. |
then the call
mtxm_c ( m1, m2, mout );
produces the matrix
mout = | -3. 5. 7. |
| |
| -3. 7. 8. |
| |
| -3. 9. 9. |
-Restrictions
The user is responsible for checking the magnitudes of the
elements of m1 and m2 so that a floating point overflow does
not occur. (In the typical use where m1 and m2 are rotation
matrices, this not a risk at all.)
-Exceptions
Error free.
-Files
None
-Author_and_Institution
W.M. Owen (JPL)
E.D Wright (JPL)
-Literature_References
None.
-Version
-CSPICE Version 1.0.0, 16-APR-1999 (EDW)
-Index_Entries
matrix_transpose times matrix 3x3_case
-&
*/
{ /* Begin mtxm_c */
/*
Local variables
*/
SpiceInt i;
SpiceInt j;
SpiceDouble mtemp[3][3];
for ( i = 0; i < 3; i++ )
{
for ( j = 0; j < 3; j++ )
{
mtemp[i][j] = m1[0][i] * m2[0][j]
+ m1[1][i] * m2[1][j]
+ m1[2][i] * m2[2][j];
}
}
/*
Copy the results from the temporary matrix to the return matrix.
*/
MOVED ( mtemp, 9, mout );
} /* End mtxm_c */
void vequg_c ( ConstSpiceDouble * vin,
SpiceInt ndim,
SpiceDouble * vout )
/*
-Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
vin I ndim-dimensional double precision vector.
ndim I Dimension of vin (and also vout).
vout O ndim-dimensional double precision vector set
equal to vin.
-Detailed_Input
vin is a double precision vector of arbitrary dimension.
ndim is the number of components of vin.
-Detailed_Output
vout is a double precision vector set equal to vin.
-Parameters
None.
-Particulars
The code simply sets each component of vout equal to the
corresponding component of vin.
-Examples
Let state be a state vector. Set abstat equal to state.
vequg_c ( state, 6, abstate );
Note that this routine may be used in place of MOVED, which
sets each output array element equal to the corresponding
input array element.
-Restrictions
None.
-Exceptions
1) If ndim is not physically realistic, greater than zero, a
BADDIMENSION error is flagged.
-Files
None.
-Author_and_Institution
W.M. Owen (JPL)
E.D. Wright (JPL)
-Literature_References
None.
-Version
-CSPICE Version 1.0.0, 23-AUG-1999 (EDW) (NJB)
-Index_Entries
assign an n-dimensional vector to another
-&
*/
{ /* Begin vequg_c */
/*
Use discovery check-in.
*/
/* Check ndim is cool. Dimension is positive definite. */
if ( ndim <= 0 )
{
chkin_c ( "vequg_c" );
SpiceError ( "Vector dimension less than or equal to zero",
"BADDIMENSION" );
chkout_c ( "vequg_c" );
return;
}
/* Do the equality thing. */
MOVED ( vin, ndim, vout );
} /* End vequg_c */
