aboutsummaryrefslogtreecommitdiff
path: root/math/slalib/dsep.f
diff options
context:
space:
mode:
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/dsep.f
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'math/slalib/dsep.f')
-rw-r--r--math/slalib/dsep.f61
1 files changed, 61 insertions, 0 deletions
diff --git a/math/slalib/dsep.f b/math/slalib/dsep.f
new file mode 100644
index 00000000..6e7e9fff
--- /dev/null
+++ b/math/slalib/dsep.f
@@ -0,0 +1,61 @@
+ DOUBLE PRECISION FUNCTION slDSEP (A1, B1, A2, B2)
+*+
+* - - - - -
+* D S E P
+* - - - - -
+*
+* Angle between two points on a sphere.
+*
+* (double precision)
+*
+* Given:
+* A1,B1 d spherical coordinates of one point
+* A2,B2 d spherical coordinates of the other point
+*
+* (The spherical coordinates are [RA,Dec], [Long,Lat] etc, in radians.)
+*
+* The result is the angle, in radians, between the two points. It
+* is always positive.
+*
+* Called: slDS2C, slDSEPV
+*
+* Last revision: 7 May 2000
+*
+* Copyright P.T.Wallace. All rights reserved.
+*
+* 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
+
+ DOUBLE PRECISION A1,B1,A2,B2
+
+ DOUBLE PRECISION V1(3),V2(3)
+ DOUBLE PRECISION slDSEPV
+
+
+
+* Convert coordinates from spherical to Cartesian.
+ CALL slDS2C(A1,B1,V1)
+ CALL slDS2C(A2,B2,V2)
+
+* Angle between the vectors.
+ slDSEP = slDSEPV(V1,V2)
+
+ END