int iauPvstar(double pv[2][3], double *ra, double *dec, double *pmr, double *pmd, double *px, double *rv) /* ** - - - - - - - - - - ** i a u P v s t a r ** - - - - - - - - - - ** ** Convert star position+velocity vector to catalog coordinates. ** ** This function is part of the International Astronomical Union's ** SOFA (Standards Of Fundamental Astronomy) software collection. ** ** Status: support function. ** ** Given (Note 1): ** pv double[2][3] pv-vector (AU, AU/day) ** ** Returned (Note 2): ** ra double right ascension (radians) ** dec double declination (radians) ** pmr double RA proper motion (radians/year) ** pmd double Dec proper motion (radians/year) ** px double parallax (arcsec) ** rv double radial velocity (km/s, positive = receding) ** ** Returned (function value): ** int status: ** 0 = OK ** -1 = superluminal speed (Note 5) ** -2 = null position vector ** ** Notes: ** ** 1) The specified pv-vector is the coordinate direction (and its rate ** of change) for the date at which the light leaving the star ** reached the solar-system barycenter. ** ** 2) The star data returned by this function are "observables" for an ** imaginary observer at the solar-system barycenter. Proper motion ** and radial velocity are, strictly, in terms of barycentric ** coordinate time, TCB. For most practical applications, it is ** permissible to neglect the distinction between TCB and ordinary ** "proper" time on Earth (TT/TAI). The result will, as a rule, be ** limited by the intrinsic accuracy of the proper-motion and ** radial-velocity data; moreover, the supplied pv-vector is likely ** to be merely an intermediate result (for example generated by the ** function iauStarpv), so that a change of time unit will cancel ** out overall. ** ** In accordance with normal star-catalog conventions, the object's ** right ascension and declination are freed from the effects of ** secular aberration. The frame, which is aligned to the catalog ** equator and equinox, is Lorentzian and centered on the SSB. ** ** Summarizing, the specified pv-vector is for most stars almost ** identical to the result of applying the standard geometrical ** "space motion" transformation to the catalog data. The ** differences, which are the subject of the Stumpff paper cited ** below, are: ** ** (i) In stars with significant radial velocity and proper motion, ** the constantly changing light-time distorts the apparent proper ** motion. Note that this is a classical, not a relativistic, ** effect. ** ** (ii) The transformation complies with special relativity. ** ** 3) Care is needed with units. The star coordinates are in radians ** and the proper motions in radians per Julian year, but the ** parallax is in arcseconds; the radial velocity is in km/s, but ** the pv-vector result is in AU and AU/day. ** ** 4) The proper motions are the rate of change of the right ascension ** and declination at the catalog epoch and are in radians per Julian ** year. The RA proper motion is in terms of coordinate angle, not ** true angle, and will thus be numerically larger at high ** declinations. ** ** 5) Straight-line motion at constant speed in the inertial frame is ** assumed. If the speed is greater than or equal to the speed of ** light, the function aborts with an error status. ** ** 6) The inverse transformation is performed by the function iauStarpv. ** ** Called: ** iauPn decompose p-vector into modulus and direction ** iauPdp scalar product of two p-vectors ** iauSxp multiply p-vector by scalar ** iauPmp p-vector minus p-vector ** iauPm modulus of p-vector ** iauPpp p-vector plus p-vector ** iauPv2s pv-vector to spherical ** iauAnp normalize angle into range 0 to 2pi ** ** Reference: ** ** Stumpff, P., 1985, Astron.Astrophys. 144, 232-240. ** ** This revision: 2013 June 18 ** ** SOFA release 2015-02-09 ** ** Copyright (C) 2015 IAU SOFA Board. See notes at end. */ { double r, x[3], vr, ur[3], vt, ut[3], bett, betr, d, w, del, usr[3], ust[3], a, rad, decd, rd; /* Isolate the radial component of the velocity (AU/day, inertial). */ iauPn(pv[0], &r, x); vr = iauPdp(x, pv[1]); iauSxp(vr, x, ur); /* Isolate the transverse component of the velocity (AU/day, inertial). */ iauPmp(pv[1], ur, ut); vt = iauPm(ut); /* Special-relativity dimensionless parameters. */ bett = vt / DC; betr = vr / DC; /* The inertial-to-observed correction terms. */ d = 1.0 + betr; w = 1.0 - betr*betr - bett*bett; if (d == 0.0 || w < 0) return -1; del = sqrt(w) - 1.0; /* Apply relativistic correction factor to radial velocity component. */ w = (betr != 0) ? (betr - del) / (betr * d) : 1.0; iauSxp(w, ur, usr); /* Apply relativistic correction factor to tangential velocity */ /* component. */ iauSxp(1.0/d, ut, ust); /* Combine the two to obtain the observed velocity vector (AU/day). */ iauPpp(usr, ust, pv[1]); /* Cartesian to spherical. */ iauPv2s(pv, &a, dec, &r, &rad, &decd, &rd); if (r == 0.0) return -2; /* Return RA in range 0 to 2pi. */ *ra = iauAnp(a); /* Return proper motions in radians per year. */ *pmr = rad * DJY; *pmd = decd * DJY; /* Return parallax in arcsec. */ *px = DR2AS / r; /* Return radial velocity in km/s. */ *rv = 1e-3 * rd * DAU / DAYSEC; /* OK status. */ return 0; /*---------------------------------------------------------------------- ** ** Copyright (C) 2015 ** Standards Of Fundamental Astronomy Board ** of the International Astronomical Union. ** ** ===================== ** SOFA Software License ** ===================== ** ** NOTICE TO USER: ** ** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND ** CONDITIONS WHICH APPLY TO ITS USE. ** ** 1. The Software is owned by the IAU SOFA Board ("SOFA"). ** ** 2. Permission is granted to anyone to use the SOFA software for any ** purpose, including commercial applications, free of charge and ** without payment of royalties, subject to the conditions and ** restrictions listed below. ** ** 3. You (the user) may copy and distribute SOFA source code to others, ** and use and adapt its code and algorithms in your own software, ** on a world-wide, royalty-free basis. That portion of your ** distribution that does not consist of intact and unchanged copies ** of SOFA source code files is a "derived work" that must comply ** with the following requirements: ** ** a) Your work shall be marked or carry a statement that it ** (i) uses routines and computations derived by you from ** software provided by SOFA under license to you; and ** (ii) does not itself constitute software provided by and/or ** endorsed by SOFA. ** ** b) The source code of your derived work must contain descriptions ** of how the derived work is based upon, contains and/or differs ** from the original SOFA software. ** ** c) The names of all routines in your derived work shall not ** include the prefix "iau" or "sofa" or trivial modifications ** thereof such as changes of case. ** ** d) The origin of the SOFA components of your derived work must ** not be misrepresented; you must not claim that you wrote the ** original software, nor file a patent application for SOFA ** software or algorithms embedded in the SOFA software. ** ** e) These requirements must be reproduced intact in any source ** distribution and shall apply to anyone to whom you have ** granted a further right to modify the source code of your ** derived work. ** ** Note that, as originally distributed, the SOFA software is ** intended to be a definitive implementation of the IAU standards, ** and consequently third-party modifications are discouraged. All ** variations, no matter how minor, must be explicitly marked as ** such, as explained above. ** ** 4. You shall not cause the SOFA software to be brought into ** disrepute, either by misuse, or use for inappropriate tasks, or ** by inappropriate modification. ** ** 5. The SOFA software is provided "as is" and SOFA makes no warranty ** as to its use or performance. SOFA does not and cannot warrant ** the performance or results which the user may obtain by using the ** SOFA software. SOFA makes no warranties, express or implied, as ** to non-infringement of third party rights, merchantability, or ** fitness for any particular purpose. In no event will SOFA be ** liable to the user for any consequential, incidental, or special ** damages, including any lost profits or lost savings, even if a ** SOFA representative has been advised of such damages, or for any ** claim by any third party. ** ** 6. The provision of any version of the SOFA software under the terms ** and conditions specified herein does not imply that future ** versions will also be made available under the same terms and ** conditions. * ** In any published work or commercial product which uses the SOFA ** software directly, acknowledgement (see www.iausofa.org) is ** appreciated. ** ** Correspondence concerning SOFA software should be addressed as ** follows: ** ** By email: [email protected] ** By post: IAU SOFA Center ** HM Nautical Almanac Office ** UK Hydrographic Office ** Admiralty Way, Taunton ** Somerset, TA1 2DN ** United Kingdom ** **--------------------------------------------------------------------*/ }
void iauHfk5z(double rh, double dh, double date1, double date2, double *r5, double *d5, double *dr5, double *dd5) /* ** - - - - - - - - - ** i a u H f k 5 z ** - - - - - - - - - ** ** Transform a Hipparcos star position into FK5 J2000.0, assuming ** zero Hipparcos proper motion. ** ** This function is part of the International Astronomical Union's ** SOFA (Standards Of Fundamental Astronomy) software collection. ** ** Status: support function. ** ** Given: ** rh double Hipparcos RA (radians) ** dh double Hipparcos Dec (radians) ** date1,date2 double TDB date (Note 1) ** ** Returned (all FK5, equinox J2000.0, date date1+date2): ** r5 double RA (radians) ** d5 double Dec (radians) ** dr5 double FK5 RA proper motion (rad/year, Note 4) ** dd5 double Dec proper motion (rad/year, Note 4) ** ** Notes: ** ** 1) The TT date date1+date2 is a Julian Date, apportioned in any ** convenient way between the two arguments. For example, ** JD(TT)=2450123.7 could be expressed in any of these ways, ** among others: ** ** date1 date2 ** ** 2450123.7 0.0 (JD method) ** 2451545.0 -1421.3 (J2000 method) ** 2400000.5 50123.2 (MJD method) ** 2450123.5 0.2 (date & time method) ** ** The JD method is the most natural and convenient to use in ** cases where the loss of several decimal digits of resolution ** is acceptable. The J2000 method is best matched to the way ** the argument is handled internally and will deliver the ** optimum resolution. The MJD method and the date & time methods ** are both good compromises between resolution and convenience. ** ** 2) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt. ** ** 3) The FK5 to Hipparcos transformation is modeled as a pure rotation ** and spin; zonal errors in the FK5 catalogue are not taken into ** account. ** ** 4) It was the intention that Hipparcos should be a close ** approximation to an inertial frame, so that distant objects have ** zero proper motion; such objects have (in general) non-zero ** proper motion in FK5, and this function returns those fictitious ** proper motions. ** ** 5) The position returned by this function is in the FK5 J2000.0 ** reference system but at date date1+date2. ** ** 6) See also iauFk52h, iauH2fk5, iauFk5zhz. ** ** Called: ** iauS2c spherical coordinates to unit vector ** iauFk5hip FK5 to Hipparcos rotation and spin ** iauRxp product of r-matrix and p-vector ** iauSxp multiply p-vector by scalar ** iauRxr product of two r-matrices ** iauTrxp product of transpose of r-matrix and p-vector ** iauPxp vector product of two p-vectors ** iauPv2s pv-vector to spherical ** iauAnp normalize angle into range 0 to 2pi ** ** Reference: ** ** F.Mignard & M.Froeschle, 2000, Astron.Astrophys. 354, 732-739. ** ** This revision: 2013 June 18 ** ** SOFA release 2013-12-02 ** ** Copyright (C) 2013 IAU SOFA Board. See notes at end. */ { double t, ph[3], r5h[3][3], s5h[3], sh[3], vst[3], rst[3][3], r5ht[3][3], pv5e[2][3], vv[3], w, r, v; /* Time interval from fundamental epoch J2000.0 to given date (JY). */ t = ((date1 - DJ00) + date2) / DJY; /* Hipparcos barycentric position vector (normalized). */ iauS2c(rh, dh, ph); /* FK5 to Hipparcos orientation matrix and spin vector. */ iauFk5hip(r5h, s5h); /* Rotate the spin into the Hipparcos system. */ iauRxp(r5h, s5h, sh); /* Accumulated Hipparcos wrt FK5 spin over that interval. */ iauSxp(t, s5h, vst); /* Express the accumulated spin as a rotation matrix. */ iauRv2m(vst, rst); /* Rotation matrix: accumulated spin, then FK5 to Hipparcos. */ iauRxr(r5h, rst, r5ht); /* De-orient & de-spin the Hipparcos position into FK5 J2000.0. */ iauTrxp(r5ht, ph, pv5e[0]); /* Apply spin to the position giving a space motion. */ iauPxp(sh, ph, vv); /* De-orient & de-spin the Hipparcos space motion into FK5 J2000.0. */ iauTrxp(r5ht, vv, pv5e[1]); /* FK5 position/velocity pv-vector to spherical. */ iauPv2s(pv5e, &w, d5, &r, dr5, dd5, &v); *r5 = iauAnp(w); return; /*---------------------------------------------------------------------- ** ** Copyright (C) 2013 ** Standards Of Fundamental Astronomy Board ** of the International Astronomical Union. ** ** ===================== ** SOFA Software License ** ===================== ** ** NOTICE TO USER: ** ** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND ** CONDITIONS WHICH APPLY TO ITS USE. ** ** 1. The Software is owned by the IAU SOFA Board ("SOFA"). ** ** 2. Permission is granted to anyone to use the SOFA software for any ** purpose, including commercial applications, free of charge and ** without payment of royalties, subject to the conditions and ** restrictions listed below. ** ** 3. You (the user) may copy and distribute SOFA source code to others, ** and use and adapt its code and algorithms in your own software, ** on a world-wide, royalty-free basis. That portion of your ** distribution that does not consist of intact and unchanged copies ** of SOFA source code files is a "derived work" that must comply ** with the following requirements: ** ** a) Your work shall be marked or carry a statement that it ** (i) uses routines and computations derived by you from ** software provided by SOFA under license to you; and ** (ii) does not itself constitute software provided by and/or ** endorsed by SOFA. ** ** b) The source code of your derived work must contain descriptions ** of how the derived work is based upon, contains and/or differs ** from the original SOFA software. ** ** c) The names of all routines in your derived work shall not ** include the prefix "iau" or "sofa" or trivial modifications ** thereof such as changes of case. ** ** d) The origin of the SOFA components of your derived work must ** not be misrepresented; you must not claim that you wrote the ** original software, nor file a patent application for SOFA ** software or algorithms embedded in the SOFA software. ** ** e) These requirements must be reproduced intact in any source ** distribution and shall apply to anyone to whom you have ** granted a further right to modify the source code of your ** derived work. ** ** Note that, as originally distributed, the SOFA software is ** intended to be a definitive implementation of the IAU standards, ** and consequently third-party modifications are discouraged. All ** variations, no matter how minor, must be explicitly marked as ** such, as explained above. ** ** 4. You shall not cause the SOFA software to be brought into ** disrepute, either by misuse, or use for inappropriate tasks, or ** by inappropriate modification. ** ** 5. The SOFA software is provided "as is" and SOFA makes no warranty ** as to its use or performance. SOFA does not and cannot warrant ** the performance or results which the user may obtain by using the ** SOFA software. SOFA makes no warranties, express or implied, as ** to non-infringement of third party rights, merchantability, or ** fitness for any particular purpose. In no event will SOFA be ** liable to the user for any consequential, incidental, or special ** damages, including any lost profits or lost savings, even if a ** SOFA representative has been advised of such damages, or for any ** claim by any third party. ** ** 6. The provision of any version of the SOFA software under the terms ** and conditions specified herein does not imply that future ** versions will also be made available under the same terms and ** conditions. * ** In any published work or commercial product which uses the SOFA ** software directly, acknowledgement (see www.iausofa.org) is ** appreciated. ** ** Correspondence concerning SOFA software should be addressed as ** follows: ** ** By email: [email protected] ** By post: IAU SOFA Center ** HM Nautical Almanac Office ** UK Hydrographic Office ** Admiralty Way, Taunton ** Somerset, TA1 2DN ** United Kingdom ** **--------------------------------------------------------------------*/ }
int iauStarpv(double ra, double dec, double pmr, double pmd, double px, double rv, double pv[2][3]) /* ** - - - - - - - - - - ** i a u S t a r p v ** - - - - - - - - - - ** ** Convert star catalog coordinates to position+velocity vector. ** ** Status: support function. ** ** Given (Note 1): ** ra double right ascension (radians) ** dec double declination (radians) ** pmr double RA proper motion (radians/year) ** pmd double Dec proper motion (radians/year) ** px double parallax (arcseconds) ** rv double radial velocity (km/s, positive = receding) ** ** Returned (Note 2): ** pv double[2][3] pv-vector (AU, AU/day) ** ** Returned (function value): ** int status: ** 0 = no warnings ** 1 = distance overridden (Note 6) ** 2 = excessive speed (Note 7) ** 4 = solution didn't converge (Note 8) ** else = binary logical OR of the above ** ** Notes: ** ** 1) The star data accepted by this function are "observables" for an ** imaginary observer at the solar-system barycenter. Proper motion ** and radial velocity are, strictly, in terms of barycentric ** coordinate time, TCB. For most practical applications, it is ** permissible to neglect the distinction between TCB and ordinary ** "proper" time on Earth (TT/TAI). The result will, as a rule, be ** limited by the intrinsic accuracy of the proper-motion and ** radial-velocity data; moreover, the pv-vector is likely to be ** merely an intermediate result, so that a change of time unit ** would cancel out overall. ** ** In accordance with normal star-catalog conventions, the object's ** right ascension and declination are freed from the effects of ** secular aberration. The frame, which is aligned to the catalog ** equator and equinox, is Lorentzian and centered on the SSB. ** ** 2) The resulting position and velocity pv-vector is with respect to ** the same frame and, like the catalog coordinates, is freed from ** the effects of secular aberration. Should the "coordinate ** direction", where the object was located at the catalog epoch, be ** required, it may be obtained by calculating the magnitude of the ** position vector pv[0][0-2] dividing by the speed of light in ** AU/day to give the light-time, and then multiplying the space ** velocity pv[1][0-2] by this light-time and adding the result to ** pv[0][0-2]. ** ** Summarizing, the pv-vector returned is for most stars almost ** identical to the result of applying the standard geometrical ** "space motion" transformation. The differences, which are the ** subject of the Stumpff paper referenced below, are: ** ** (i) In stars with significant radial velocity and proper motion, ** the constantly changing light-time distorts the apparent proper ** motion. Note that this is a classical, not a relativistic, ** effect. ** ** (ii) The transformation complies with special relativity. ** ** 3) Care is needed with units. The star coordinates are in radians ** and the proper motions in radians per Julian year, but the ** parallax is in arcseconds; the radial velocity is in km/s, but ** the pv-vector result is in AU and AU/day. ** ** 4) The RA proper motion is in terms of coordinate angle, not true ** angle. If the catalog uses arcseconds for both RA and Dec proper ** motions, the RA proper motion will need to be divided by cos(Dec) ** before use. ** ** 5) Straight-line motion at constant speed, in the inertial frame, ** is assumed. ** ** 6) An extremely small (or zero or negative) parallax is interpreted ** to mean that the object is on the "celestial sphere", the radius ** of which is an arbitrary (large) value (see the constant PXMIN). ** When the distance is overridden in this way, the status, ** initially zero, has 1 added to it. ** ** 7) If the space velocity is a significant fraction of c (see the ** constant VMAX), it is arbitrarily set to zero. When this action ** occurs, 2 is added to the status. ** ** 8) The relativistic adjustment involves an iterative calculation. ** If the process fails to converge within a set number (IMAX) of ** iterations, 4 is added to the status. ** ** 9) The inverse transformation is performed by the function ** iauPvstar. ** ** Called: ** iauS2pv spherical coordinates to pv-vector ** iauPm modulus of p-vector ** iauZp zero p-vector ** iauPn decompose p-vector into modulus and direction ** iauPdp scalar product of two p-vectors ** iauSxp multiply p-vector by scalar ** iauPmp p-vector minus p-vector ** iauPpp p-vector plus p-vector ** ** Reference: ** ** Stumpff, P., 1985, Astron.Astrophys. 144, 232-240. ** ** This revision: 2009 July 6 ** ** Original version 2012-03-01 ** ** Copyright (C) 2013 Naoki Arita. See notes at end. */ { /* Smallest allowed parallax */ static const double PXMIN = 1e-7; /* Largest allowed speed (fraction of c) */ static const double VMAX = 0.5; /* Maximum number of iterations for relativistic solution */ static const int IMAX = 100; int i, iwarn; double w, r, rd, rad, decd, v, x[3], usr[3], ust[3], vsr, vst, betst, betsr, bett, betr, dd, ddel, ur[3], ut[3], d = 0.0, del = 0.0, /* to prevent */ odd = 0.0, oddel = 0.0, /* compiler */ od = 0.0, odel = 0.0; /* warnings */ /* Distance (AU). */ if (px >= PXMIN) { w = px; iwarn = 0; } else { w = PXMIN; iwarn = 1; } r = DR2AS / w; /* Radial velocity (AU/day). */ rd = DAYSEC * rv * 1e3 / DAU; /* Proper motion (radian/day). */ rad = pmr / DJY; decd = pmd / DJY; /* To pv-vector (AU,AU/day). */ iauS2pv(ra, dec, r, rad, decd, rd, pv); /* If excessive velocity, arbitrarily set it to zero. */ v = iauPm(pv[1]); if (v / DC > VMAX) { iauZp(pv[1]); iwarn += 2; } /* Isolate the radial component of the velocity (AU/day). */ iauPn(pv[0], &w, x); vsr = iauPdp(x, pv[1]); iauSxp(vsr, x, usr); /* Isolate the transverse component of the velocity (AU/day). */ iauPmp(pv[1], usr, ust); vst = iauPm(ust); /* Special-relativity dimensionless parameters. */ betsr = vsr / DC; betst = vst / DC; /* Determine the inertial-to-observed relativistic correction terms. */ bett = betst; betr = betsr; for (i = 0; i < IMAX; i++) { d = 1.0 + betr; del = sqrt(1.0 - betr*betr - bett*bett) - 1.0; betr = d * betsr + del; bett = d * betst; if (i > 0) { dd = fabs(d - od); ddel = fabs(del - odel); if ((i > 1) && (dd >= odd) && (ddel >= oddel)) break; odd = dd; oddel = ddel; } od = d; odel = del; } if (i >= IMAX) iwarn += 4; /* Replace observed radial velocity with inertial value. */ w = (betsr != 0.0) ? d + del / betsr : 1.0; iauSxp(w, usr, ur); /* Replace observed tangential velocity with inertial value. */ iauSxp(d, ust, ut); /* Combine the two to obtain the inertial space velocity. */ iauPpp(ur, ut, pv[1]); /* Return the status. */ return iwarn; /*---------------------------------------------------------------------- ** ** Celes is a wrapper of the SOFA Library for Ruby. ** ** This file is redistributed and relicensed in accordance with ** the SOFA Software License (http://www.iausofa.org/tandc.html). ** ** The original library is available from IAU Standards of ** Fundamental Astronomy (http://www.iausofa.org/). ** ** ** ** ** ** Copyright (C) 2013, Naoki Arita ** All rights reserved. ** ** Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions ** are met: ** ** 1 Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** ** 2 Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** ** 3 Neither the name of the Standards Of Fundamental Astronomy Board, ** the International Astronomical Union nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ** POSSIBILITY OF SUCH DAMAGE. ** **--------------------------------------------------------------------*/ }
void iauS2xpv(double s1, double s2, double pv[2][3], double spv[2][3]) /* ** - - - - - - - - - ** i a u S 2 x p v ** - - - - - - - - - ** ** Multiply a pv-vector by two scalars. ** ** This function is part of the International Astronomical Union's ** SOFA (Standards Of Fundamental Astronomy) software collection. ** ** Status: vector/matrix support function. ** ** Given: ** s1 double scalar to multiply position component by ** s2 double scalar to multiply velocity component by ** pv double[2][3] pv-vector ** ** Returned: ** spv double[2][3] pv-vector: p scaled by s1, v scaled by s2 ** ** Note: ** It is permissible for pv and spv to be the same array. ** ** Called: ** iauSxp multiply p-vector by scalar ** ** This revision: 2013 June 18 ** ** SOFA release 2015-02-09 ** ** Copyright (C) 2015 IAU SOFA Board. See notes at end. */ { iauSxp(s1, pv[0], spv[0]); iauSxp(s2, pv[1], spv[1]); return; /*---------------------------------------------------------------------- ** ** Copyright (C) 2015 ** Standards Of Fundamental Astronomy Board ** of the International Astronomical Union. ** ** ===================== ** SOFA Software License ** ===================== ** ** NOTICE TO USER: ** ** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND ** CONDITIONS WHICH APPLY TO ITS USE. ** ** 1. The Software is owned by the IAU SOFA Board ("SOFA"). ** ** 2. Permission is granted to anyone to use the SOFA software for any ** purpose, including commercial applications, free of charge and ** without payment of royalties, subject to the conditions and ** restrictions listed below. ** ** 3. You (the user) may copy and distribute SOFA source code to others, ** and use and adapt its code and algorithms in your own software, ** on a world-wide, royalty-free basis. That portion of your ** distribution that does not consist of intact and unchanged copies ** of SOFA source code files is a "derived work" that must comply ** with the following requirements: ** ** a) Your work shall be marked or carry a statement that it ** (i) uses routines and computations derived by you from ** software provided by SOFA under license to you; and ** (ii) does not itself constitute software provided by and/or ** endorsed by SOFA. ** ** b) The source code of your derived work must contain descriptions ** of how the derived work is based upon, contains and/or differs ** from the original SOFA software. ** ** c) The names of all routines in your derived work shall not ** include the prefix "iau" or "sofa" or trivial modifications ** thereof such as changes of case. ** ** d) The origin of the SOFA components of your derived work must ** not be misrepresented; you must not claim that you wrote the ** original software, nor file a patent application for SOFA ** software or algorithms embedded in the SOFA software. ** ** e) These requirements must be reproduced intact in any source ** distribution and shall apply to anyone to whom you have ** granted a further right to modify the source code of your ** derived work. ** ** Note that, as originally distributed, the SOFA software is ** intended to be a definitive implementation of the IAU standards, ** and consequently third-party modifications are discouraged. All ** variations, no matter how minor, must be explicitly marked as ** such, as explained above. ** ** 4. You shall not cause the SOFA software to be brought into ** disrepute, either by misuse, or use for inappropriate tasks, or ** by inappropriate modification. ** ** 5. The SOFA software is provided "as is" and SOFA makes no warranty ** as to its use or performance. SOFA does not and cannot warrant ** the performance or results which the user may obtain by using the ** SOFA software. SOFA makes no warranties, express or implied, as ** to non-infringement of third party rights, merchantability, or ** fitness for any particular purpose. In no event will SOFA be ** liable to the user for any consequential, incidental, or special ** damages, including any lost profits or lost savings, even if a ** SOFA representative has been advised of such damages, or for any ** claim by any third party. ** ** 6. The provision of any version of the SOFA software under the terms ** and conditions specified herein does not imply that future ** versions will also be made available under the same terms and ** conditions. * ** In any published work or commercial product which uses the SOFA ** software directly, acknowledgement (see www.iausofa.org) is ** appreciated. ** ** Correspondence concerning SOFA software should be addressed as ** follows: ** ** By email: [email protected] ** By post: IAU SOFA Center ** HM Nautical Almanac Office ** UK Hydrographic Office ** Admiralty Way, Taunton ** Somerset, TA1 2DN ** United Kingdom ** **--------------------------------------------------------------------*/ }
void iauPn(double p[3], double *r, double u[3]) /* ** - - - - - - ** i a u P n ** - - - - - - ** ** Convert a p-vector into modulus and unit vector. ** ** Status: vector/matrix support function. ** ** Given: ** p double[3] p-vector ** ** Returned: ** r double modulus ** u double[3] unit vector ** ** Notes: ** ** 1) If p is null, the result is null. Otherwise the result is a unit ** vector. ** ** 2) It is permissible to re-use the same array for any of the ** arguments. ** ** Called: ** iauPm modulus of p-vector ** iauZp zero p-vector ** iauSxp multiply p-vector by scalar ** ** This revision: 2008 November 18 ** ** Original version 2012-03-01 ** ** Copyright (C) 2013 Naoki Arita. See notes at end. */ { double w; /* Obtain the modulus and test for zero. */ w = iauPm(p); if (w == 0.0) { /* Null vector. */ iauZp(u); } else { /* Unit vector. */ iauSxp(1.0/w, p, u); } /* Return the modulus. */ *r = w; return; /*---------------------------------------------------------------------- ** ** Celes is a wrapper of the SOFA Library for Ruby. ** ** This file is redistributed and relicensed in accordance with ** the SOFA Software License (http://www.iausofa.org/tandc.html). ** ** The original library is available from IAU Standards of ** Fundamental Astronomy (http://www.iausofa.org/). ** ** ** ** ** ** Copyright (C) 2013, Naoki Arita ** All rights reserved. ** ** Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions ** are met: ** ** 1 Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** ** 2 Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** ** 3 Neither the name of the Standards Of Fundamental Astronomy Board, ** the International Astronomical Union nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ** POSSIBILITY OF SUCH DAMAGE. ** **--------------------------------------------------------------------*/ }