coyote: CGREVERSEINDICES

• coyote/Utilities
• [Source code]

Description

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.

Categories

Utilities

Params

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. 

Keywords

count: out, optional, type=Long
    The number of indices returned by the function.

Return Value

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.

Examples

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      =          948
       LONG      =          948
   IDL> image[indices] = 0

Author

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

History

Written by David W. Fanning at suggestion of Ben Tupper. 7 January 2011.

Copyright

Copyright (c) 2011, Fanning Software Consulting, Inc.