diff options
Diffstat (limited to 'sys/vops/ak/ahgml.x')
-rw-r--r-- | sys/vops/ak/ahgml.x | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/sys/vops/ak/ahgml.x b/sys/vops/ak/ahgml.x new file mode 100644 index 00000000..f515a2e4 --- /dev/null +++ b/sys/vops/ak/ahgml.x @@ -0,0 +1,39 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <mach.h> + +# AHGM -- Accumulate the histogram of the input vector. The output vector +# HGM (the histogram) should be cleared prior to the first call. + +procedure ahgml (data, npix, hgm, nbins, z1, z2) + +long data[ARB] # data vector +int npix # number of pixels +int hgm[ARB] # output histogram +int nbins # number of bins in histogram +long z1, z2 # greyscale values of first and last bins + +long z +real dz +int bin, i + +begin + dz = real (nbins - 1) / real (z2 - z1) + if (abs (dz - 1.0) < (EPSILONR * 2.0)) { + do i = 1, npix { + z = data[i] + if (z >= z1 && z <= z2) { + bin = int (z - z1) + 1 + hgm[bin] = hgm[bin] + 1 + } + } + } else { + do i = 1, npix { + z = data[i] + if (z >= z1 && z <= z2) { + bin = int ((z - z1) * dz) + 1 + hgm[bin] = hgm[bin] + 1 + } + } + } +end |