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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 /noao/astutil/asttools/astdsun.x
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'noao/astutil/asttools/astdsun.x')
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diff --git a/noao/astutil/asttools/astdsun.x b/noao/astutil/asttools/astdsun.x
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+include <math.h>
+
+# AST_DSUN -- Distance to Sun in AU
+# Taken from Astronomical Almanac 1984, page C24.
+
+double procedure ast_dsun (epoch)
+
+double epoch # Epoch desired
+
+double n, g, r
+double ast_julday()
+
+begin
+ n = ast_julday (epoch) - 2451545d0
+ g = DEGTORAD (357.528d0 + 0.9856003d0 * n)
+ r = 1.00014d0 - 0.01671d0 * cos (g) - 0.00014d0 * cos (2 * g)
+
+ return (r)
+end