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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/vops/lz/aravd.x
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <mach.h>
+
+# ARAV -- Compute the mean and standard deviation of a sample array by
+# iteratively rejecting points further than KSIG from the mean. If the
+# value of KSIG is given as 0.0, a cutoff value will be automatically
+# calculated from the standard deviation and number of points in the sample.
+# The number of pixels remaining in the sample upon termination is returned
+# as the function value.
+
+int procedure aravd (a, npix, mean, sigma, ksig)
+
+double a[ARB] # input data array
+double mean, sigma, ksig, deviation, lcut, hcut, lgpx
+int npix, ngpix, old_ngpix, awvgd()
+
+begin
+ lcut = -MAX_REAL # no rejection to start
+ hcut = MAX_REAL
+ ngpix = MAX_INT
+
+ # Iteratively compute mean, sigma and reject outliers until no
+ # more pixels are rejected, or until there are no more pixels.
+
+ repeat {
+ old_ngpix = ngpix
+ ngpix = awvgd (a, npix, mean, sigma, lcut, hcut)
+ if (ngpix <= 1 || sigma <= EPSILOND)
+ break
+
+ if (ksig == 0.0) { # Chauvenet's relation
+ lgpx = log10 (real(ngpix))
+ deviation = (lgpx * (-0.1042 * lgpx + 1.1695) + .8895) * sigma
+ } else
+ deviation = sigma * abs(ksig)
+
+ lcut = mean - deviation # compute window
+ hcut = mean + deviation
+
+ } until (ngpix >= old_ngpix)
+
+ return (ngpix)
+end