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author | William Joye <wjoye@cfa.harvard.edu> | 2018-09-21 17:02:41 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2018-09-21 17:02:41 (GMT) |
commit | bd7d67f66c53df36bb50e3423bfc91eae8618201 (patch) | |
tree | 343b06f7a9f2decdfa8d3e4aae885be3e909aa14 /ast/erfa/pap.c | |
parent | f2f490ba0f98917b590fd7e538b9514e4119e640 (diff) | |
download | blt-bd7d67f66c53df36bb50e3423bfc91eae8618201.zip blt-bd7d67f66c53df36bb50e3423bfc91eae8618201.tar.gz blt-bd7d67f66c53df36bb50e3423bfc91eae8618201.tar.bz2 |
update ast
Diffstat (limited to 'ast/erfa/pap.c')
-rw-r--r-- | ast/erfa/pap.c | 148 |
1 files changed, 0 insertions, 148 deletions
diff --git a/ast/erfa/pap.c b/ast/erfa/pap.c deleted file mode 100644 index afd8651..0000000 --- a/ast/erfa/pap.c +++ /dev/null @@ -1,148 +0,0 @@ -#include "erfa.h" - -double eraPap(double a[3], double b[3]) -/* -** - - - - - - - -** e r a P a p -** - - - - - - - -** -** Position-angle from two p-vectors. -** -** Given: -** a double[3] direction of reference point -** b double[3] direction of point whose PA is required -** -** Returned (function value): -** double position angle of b with respect to a (radians) -** -** Notes: -** -** 1) The result is the position angle, in radians, of direction b with -** respect to direction a. It is in the range -pi to +pi. The -** sense is such that if b is a small distance "north" of a the -** position angle is approximately zero, and if b is a small -** distance "east" of a the position angle is approximately +pi/2. -** -** 2) The vectors a and b need not be of unit length. -** -** 3) Zero is returned if the two directions are the same or if either -** vector is null. -** -** 4) If vector a is at a pole, the result is ill-defined. -** -** Called: -** eraPn decompose p-vector into modulus and direction -** eraPm modulus of p-vector -** eraPxp vector product of two p-vectors -** eraPmp p-vector minus p-vector -** eraPdp scalar product of two p-vectors -** -** Copyright (C) 2013-2016, NumFOCUS Foundation. -** Derived, with permission, from the SOFA library. See notes at end of file. -*/ -{ - double am, au[3], bm, st, ct, xa, ya, za, eta[3], xi[3], a2b[3], pa; - - -/* Modulus and direction of the a vector. */ - eraPn(a, &am, au); - -/* Modulus of the b vector. */ - bm = eraPm(b); - -/* Deal with the case of a null vector. */ - if ((am == 0.0) || (bm == 0.0)) { - st = 0.0; - ct = 1.0; - } else { - - /* The "north" axis tangential from a (arbitrary length). */ - xa = a[0]; - ya = a[1]; - za = a[2]; - eta[0] = -xa * za; - eta[1] = -ya * za; - eta[2] = xa*xa + ya*ya; - - /* The "east" axis tangential from a (same length). */ - eraPxp(eta, au, xi); - - /* The vector from a to b. */ - eraPmp(b, a, a2b); - - /* Resolve into components along the north and east axes. */ - st = eraPdp(a2b, xi); - ct = eraPdp(a2b, eta); - - /* Deal with degenerate cases. */ - if ((st == 0.0) && (ct == 0.0)) ct = 1.0; - } - -/* Position angle. */ - pa = atan2(st, ct); - - return pa; - -} -/*---------------------------------------------------------------------- -** -** -** Copyright (C) 2013-2016, NumFOCUS Foundation. -** All rights reserved. -** -** This library is derived, with permission, from the International -** Astronomical Union's "Standards of Fundamental Astronomy" library, -** available from http://www.iausofa.org. -** -** The ERFA version is intended to retain identical functionality to -** the SOFA library, but made distinct through different function and -** file names, as set out in the SOFA license conditions. The SOFA -** original has a role as a reference standard for the IAU and IERS, -** and consequently redistribution is permitted only in its unaltered -** state. The ERFA version is not subject to this restriction and -** therefore can be included in distributions which do not support the -** concept of "read only" software. -** -** Although the intent is to replicate the SOFA API (other than -** replacement of prefix names) and results (with the exception of -** bugs; any that are discovered will be fixed), SOFA is not -** responsible for any errors found in this version of the library. -** -** If you wish to acknowledge the SOFA heritage, please acknowledge -** that you are using a library derived from SOFA, rather than SOFA -** itself. -** -** -** TERMS AND CONDITIONS -** -** 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. -** -*/ |