Provides a simple way to obtain the data indices from a Histogram REVERSE_INDICES vector. Returns a -1 if no indices are available. Check the COUNT keyword for the number of indices returned.
Utilities
ri: in, required, type=integer The REVERSE_INDICES vector that is returned from the HISTOGRAM command. index: in, required, type=integer The zero-based index into the REVERSE_INDICES vector from which to obtain the indices. For example, an index value of 4 will return the indices in the 5th bin (zero based counting) of the histogram.
count: out, optional, type=Long The number of indices returned by the function.
indices: The indices that were put into the indexth bin of the histogram. A -1 is returned if no indices are in that particular bin.
Used with the HISTOGRAM command:: IDL> image = cgDemoData(7) IDL> h = Histogram(image, REVERSE_INDICES=ri) IDL> indices = cgReverseIndices(ri, 4, COUNT=cnt) IDL> Help, indices, cnt, h[4] INDICES LONG = Array[948] CNT LONG = 948LONG = 948 IDL> image[indices] = 0
FANNING SOFTWARE CONSULTING:: David W. Fanning 1645 Sheely Drive Fort Collins, CO 80526 USA Phone: 970-221-0438 E-mail: david@idlcoyote.com Coyote's Guide to IDL Programming: http://www.idlcoyote.com
Written by David W. Fanning at suggestion of Ben Tupper. 7 January 2011.
Copyright (c) 2011, Fanning Software Consulting, Inc.