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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 /sys/gio/fpnormd.x
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'sys/gio/fpnormd.x')
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diff --git a/sys/gio/fpnormd.x b/sys/gio/fpnormd.x
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <mach.h>
+
+# FP_NORMD -- Normalize a double precision number x to the value NORMX, in the
+# range [1-10). EXPON is returned such that x = normx * (10.0d0 ** expon).
+
+procedure fp_normd (x, normx, expon)
+
+double x # number to be normalized
+double normx # X normalized to the range 1-10 (output)
+int expon # exponent of normalized X
+double absx, tol
+
+begin
+ tol = EPSILOND * 10.0D0
+ absx = abs (x)
+ expon = 0
+
+ if (absx > 0) {
+ while (absx < (1.0D0 - tol)) {
+ absx = absx * 10.0D0
+ expon = expon - 1
+ if (absx == 0.0D0) { # check for underflow to zero
+ normx = 0
+ expon = 0
+ return
+ }
+ }
+ while (absx >= (10.0D0 + tol)) {
+ absx = absx / 10.0D0
+ expon = expon + 1
+ }
+ }
+
+ if (x < 0)
+ normx = -absx
+ else
+ normx = absx
+end