From d54fe7c1f704a63824c5bfa0ece65245572e9b27 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 4 Mar 2015 21:21:30 -0500
Subject: Initial commit

---
 src/slalib/cc2s.f | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 src/slalib/cc2s.f

(limited to 'src/slalib/cc2s.f')

diff --git a/src/slalib/cc2s.f b/src/slalib/cc2s.f
new file mode 100644
index 0000000..2e24b9d
--- /dev/null
+++ b/src/slalib/cc2s.f
@@ -0,0 +1,53 @@
+      SUBROUTINE sla_CC2S (V, A, B)
+*+
+*     - - - - -
+*      C C 2 S
+*     - - - - -
+*
+*  Direction cosines to spherical coordinates (single precision)
+*
+*  Given:
+*     V     r(3)   x,y,z vector
+*
+*  Returned:
+*     A,B   r      spherical coordinates in radians
+*
+*  The spherical coordinates are longitude (+ve anticlockwise
+*  looking from the +ve latitude pole) and latitude.  The
+*  Cartesian coordinates are right handed, with the x axis
+*  at zero longitude and latitude, and the z axis at the
+*  +ve latitude pole.
+*
+*  If V is null, zero A and B are returned.
+*  At either pole, zero A is returned.
+*
+*  P.T.Wallace   Starlink   July 1989
+*
+*  Copyright (C) 1995 Rutherford Appleton Laboratory
+*-
+
+      IMPLICIT NONE
+
+      REAL V(3),A,B
+
+      REAL X,Y,Z,R
+
+
+      X = V(1)
+      Y = V(2)
+      Z = V(3)
+      R = SQRT(X*X+Y*Y)
+
+      IF (R.EQ.0.0) THEN
+         A = 0.0
+      ELSE
+         A = ATAN2(Y,X)
+      END IF
+
+      IF (Z.EQ.0.0) THEN
+         B = 0.0
+      ELSE
+         B = ATAN2(Z,R)
+      END IF
+
+      END
-- 
cgit