coyote: CGSETINTERSECTION

Description
This function is used to find the intersection between two sets of integers.
Categories
Utilities
Returns
A vector of values that are found in both set_a and set_b.
Params
set_a: in, required, type=integer
   A vector of integers.
set_b: in, required, type=integer
   A vector of integers.
Keywords
count: out, optional, type=integer
     This keyword contains the number of elements in the intersection vector.
indices_a: out, optional, type=integer
     The indices in vector A where the intersected values appear. Note, this requires
     the intersected points be unique in each vector. The `Positions` keyword will 
     return ALL the positions of the match, even if there are non-unique matches.
indices_b: out, optional, type=integer
     The indices in vector B where the intersected values appear. This assumes that
     the intersected points are represented uniquely in the A and B vectors.
noresult: in, optional
     Set this keyword to a value that will be returned from the function
     if no intersection between the two sets of numbers is found. By default, -1.
positions: out, optional, type=integer
     This keyword returns the positions or locations in A where the values
     in B appear.
success: out, optional, type=boolean
     This keyword is set to 1 if an intersection was found, and to 0 otherwise.
Examples
Here is how to use this program::
  IDL> set_a = [1,2,3,4,5]
  IDL> set_b = [4,5,6,7,8,9,10,11]
  IDL> Print, cgSetIntersection(set_a, set_b)
       4   5
e http://www.idlcoyote.com/tips/set_operations.html for other types of set operations.
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
Change History::
   Written by: David W. Fanning, October 31, 2009, from code originally supplied to the IDL
      newsgroup by Research Systems software engineers.
   Yikes, bug in original code only allowed positive integers. Fixed now. 2 Nov 2009. DWF.
   Fixed a problem when one or both of the sets was a scalar value. 18 Nov 2009. DWF.
   Added a POSITIONS keyword. 30 Nov 2012. DWF.
   Added a COUNT keyword 3 Dec 2012. DWF.
   Added INDICES_A and INDICES_B keywords at R.G. Stockwell's suggestion. 13 Dec 2012. DWF.
Copyright
Copyright (c) 2009-2013, Fanning Software Consulting, Inc.