From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 8 Jul 2015 20:46:52 -0400
Subject: Initial commit

---
 math/slalib/cc62s.f | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 math/slalib/cc62s.f

(limited to 'math/slalib/cc62s.f')

diff --git a/math/slalib/cc62s.f b/math/slalib/cc62s.f
new file mode 100644
index 00000000..a3ad4f38
--- /dev/null
+++ b/math/slalib/cc62s.f
@@ -0,0 +1,100 @@
+      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
-- 
cgit