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authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
commit40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch)
tree4464880c571602d54f6ae114729bf62a89518057 /math/slalib/cc62s.f
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
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+ SUBROUTINE slC62S (V, A, B, R, AD, BD, RD)
+*+
+* - - - - - -
+* C 6 2 S
+* - - - - - -
+*
+* Conversion of position & velocity in Cartesian coordinates
+* to spherical coordinates (single precision)
+*
+* Given:
+* V r(6) Cartesian position & velocity vector
+*
+* Returned:
+* A r longitude (radians)
+* B r latitude (radians)
+* R r radial coordinate
+* AD r longitude derivative (radians per unit time)
+* BD r latitude derivative (radians per unit time)
+* RD r radial derivative
+*
+* P.T.Wallace Starlink 28 April 1996
+*
+* Copyright (C) 1996 Rutherford Appleton Laboratory
+*
+* License:
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program (see SLA_CONDITIONS); if not, write to the
+* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+* Boston, MA 02110-1301 USA
+*
+* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
+*-
+
+ IMPLICIT NONE
+
+ REAL V(6),A,B,R,AD,BD,RD
+
+ REAL X,Y,Z,XD,YD,ZD,RXY2,RXY,R2,XYP
+
+
+
+* Components of position/velocity vector
+ X=V(1)
+ Y=V(2)
+ Z=V(3)
+ XD=V(4)
+ YD=V(5)
+ ZD=V(6)
+
+* Component of R in XY plane squared
+ RXY2=X*X+Y*Y
+
+* Modulus squared
+ R2=RXY2+Z*Z
+
+* Protection against null vector
+ IF (R2.EQ.0.0) THEN
+ X=XD
+ Y=YD
+ Z=ZD
+ RXY2=X*X+Y*Y
+ R2=RXY2+Z*Z
+ END IF
+
+* Position and velocity in spherical coordinates
+ RXY=SQRT(RXY2)
+ XYP=X*XD+Y*YD
+ IF (RXY2.NE.0.0) THEN
+ A=ATAN2(Y,X)
+ B=ATAN2(Z,RXY)
+ AD=(X*YD-Y*XD)/RXY2
+ BD=(ZD*RXY2-Z*XYP)/(R2*RXY)
+ ELSE
+ A=0.0
+ IF (Z.NE.0.0) THEN
+ B=ATAN2(Z,RXY)
+ ELSE
+ B=0.0
+ END IF
+ AD=0.0
+ BD=0.0
+ END IF
+ R=SQRT(R2)
+ IF (R.NE.0.0) THEN
+ RD=(XYP+Z*ZD)/R
+ ELSE
+ RD=0.0
+ END IF
+
+ END