aboutsummaryrefslogtreecommitdiff
path: root/math/slalib/doc/pav.hlp
diff options
context:
space:
mode:
Diffstat (limited to 'math/slalib/doc/pav.hlp')
-rw-r--r--math/slalib/doc/pav.hlp40
1 files changed, 40 insertions, 0 deletions
diff --git a/math/slalib/doc/pav.hlp b/math/slalib/doc/pav.hlp
new file mode 100644
index 00000000..a74d3ca3
--- /dev/null
+++ b/math/slalib/doc/pav.hlp
@@ -0,0 +1,40 @@
+.help pav Jun99 "Slalib Package"
+.nf
+
+ REAL FUNCTION slPAV ( V1, V2 )
+
+ - - - -
+ P A V
+ - - - -
+
+ Position angle of one celestial direction with respect to another.
+
+ (single precision)
+
+ Given:
+ V1 r(3) direction cosines of one point
+ V2 r(3) direction cosines of the other point
+
+ (The coordinate frames correspond to RA,Dec, Long,Lat etc.)
+
+ The result is the bearing (position angle), in radians, of point
+ V2 with respect to point V1. It is in the range +/- pi. The
+ sense is such that if V2 is a small distance east of V1, the
+ bearing is about +pi/2. Zero is returned if the two points
+ are coincident.
+
+ V1 and V2 do not have to be unit vectors.
+
+ The routine slBEAR performs an equivalent function except
+ that the points are specified in the form of spherical
+ coordinates.
+
+ Called: slDPAV
+
+ Patrick Wallace Starlink 23 May 1997
+
+ Copyright (C) 1997 Rutherford Appleton Laboratory
+ Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
+
+.fi
+.endhelp