SUBROUTINE iau_FW2M ( GAMB, PHIB, PSI, EPS, R ) *+ * - - - - - - - - - * i a u _ F W 2 M * - - - - - - - - - * * Form rotation matrix given the Fukushima-Williams angles. * * This routine is part of the International Astronomical Union's * SOFA (Standards of Fundamental Astronomy) software collection. * * Status: support routine. * * Given: * GAMB d F-W angle gamma_bar (radians) * PHIB d F-W angle phi_bar (radians) * PSI d F-W angle psi (radians) * EPS d F-W angle epsilon (radians) * * Returned: * R d(3,3) rotation matrix * * Notes: * * 1) Naming the following points: * * e = J2000 ecliptic pole, * p = GCRS pole, * E = ecliptic pole of date, * and P = CIP, * * the four Fukushima-Williams angles are as follows: * * GAMB = gamma = epE * PHIB = phi = pE * PSI = psi = pEP * EPS = epsilon = EP * * 2) The matrix representing the combined effects of frame bias, * precession and nutation is: * * NxPxB = R_1(-EPS).R_3(-PSI).R_1(PHIB).R_3(GAMB) * * 3) Three different matrices can be constructed, depending on the * supplied angles: * * o To obtain the nutation x precession x frame bias matrix, * generate the four precession angles, generate the nutation * components and add them to the psi_bar and epsilon_A angles, * and call the present routine. * * o To obtain the precession x frame bias matrix, generate the * four precession angles and call the present routine. * * o To obtain the frame bias matrix, generate the four precession * angles for date J2000.0 and call the present routine. * * The nutation-only and precession-only matrices can if necessary * be obtained by combining these three appropriately. * * Called: * iau_IR initialize r-matrix to identity * iau_RZ rotate around Z-axis * iau_RX rotate around X-axis * * Reference: * * Hilton, J. et al., 2006, Celest.Mech.Dyn.Astron. 94, 351 * * This revision: 2008 January 2 * * Copyright (C) 2008 IAU SOFA Review Board. See notes at end. * *----------------------------------------------------------------------- IMPLICIT NONE DOUBLE PRECISION GAMB, PHIB, PSI, EPS, R(3,3) * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * Construct the matrix. CALL iau_IR ( R ) CALL iau_RZ ( GAMB, R ) CALL iau_RX ( PHIB, R ) CALL iau_RZ ( -PSI, R ) CALL iau_RX ( -EPS, R ) * Finished. *+----------------------------------------------------------------------- * * Copyright (C) 2008 * Standards Of Fundamental Astronomy Review Board * of the International Astronomical Union. * * ===================== * SOFA Software License * ===================== * * NOTICE TO USER: * * BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS * WHICH APPLY TO ITS USE. * * 1. The Software is owned by the IAU SOFA Review Board ("the Board"). * * 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 adapt the SOFA software and its * algorithms for your own purposes and you may copy and distribute * a resulting "derived work" to others on a world-wide, royalty-free * basis, provided that the derived work complies 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 contain * software provided by SOFA or software that has been distributed * by or endorsed by SOFA. * * b) The source code of your derived work must contain descriptions * of how the derived work is based upon and/or differs from the * original SOFA software. * * c) The name(s) of all routine(s) that you distribute shall differ * from the SOFA names, even when the SOFA content has not been * otherwise changed. * * d) The routine-naming prefix "iau" shall not be used. * * e) 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. * * f) 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. * * 4. In any published work or commercial products which includes * results achieved by using the SOFA software, you shall acknowledge * that the SOFA software was used in obtaining those results. * * 5. You shall not cause the SOFA software to be brought into * disrepute, either by misuse, or use for inappropriate tasks, or by * inappropriate modification. * * 6. The SOFA software is provided "as is" and the Board makes no * warranty as to its use or performance. The Board does not and * cannot warrant the performance or results which the user may obtain * by using the SOFA software. The Board 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 the Board be liable to the user for any consequential, * incidental, or special damages, including any lost profits or lost * savings, even if a Board representative has been advised of such * damages, or for any claim by any third party. * * 7. 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. * * Correspondence concerning SOFA software should be addressed as * follows: * * Internet email: sofa@rl.ac.uk * Postal address: IAU SOFA Center * Rutherford Appleton Laboratory * Chilton, Didcot, Oxon OX11 0QX * United Kingdom * *----------------------------------------------------------------------- END