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Diffstat (limited to 'ast/erfa/rx.c')
| -rw-r--r-- | ast/erfa/rx.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/ast/erfa/rx.c b/ast/erfa/rx.c new file mode 100644 index 0000000..2cfa460 --- /dev/null +++ b/ast/erfa/rx.c @@ -0,0 +1,119 @@ +#include "erfa.h" + +void eraRx(double phi, double r[3][3]) +/* +** - - - - - - +** e r a R x +** - - - - - - +** +** Rotate an r-matrix about the x-axis. +** +** Given: +** phi double angle (radians) +** +** Given and returned: +** r double[3][3] r-matrix, rotated +** +** Notes: +** +** 1) Calling this function with positive phi incorporates in the +** supplied r-matrix r an additional rotation, about the x-axis, +** anticlockwise as seen looking towards the origin from positive x. +** +** 2) The additional rotation can be represented by this matrix: +** +** ( 1 0 0 ) +** ( ) +** ( 0 + cos(phi) + sin(phi) ) +** ( ) +** ( 0 - sin(phi) + cos(phi) ) +** +** Copyright (C) 2013-2014, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + double s, c, a10, a11, a12, a20, a21, a22; + + + s = sin(phi); + c = cos(phi); + + a10 = c*r[1][0] + s*r[2][0]; + a11 = c*r[1][1] + s*r[2][1]; + a12 = c*r[1][2] + s*r[2][2]; + a20 = - s*r[1][0] + c*r[2][0]; + a21 = - s*r[1][1] + c*r[2][1]; + a22 = - s*r[1][2] + c*r[2][2]; + + r[1][0] = a10; + r[1][1] = a11; + r[1][2] = a12; + r[2][0] = a20; + r[2][1] = a21; + r[2][2] = a22; + + return; + +} +/*---------------------------------------------------------------------- +** +** +** Copyright (C) 2013-2014, 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. +** +*/ |