coyote: CGSETUNION

Description
This function is used to find the union between two sets of integers.
 One alternative for the cgSetUnion algorithm, provided by Maarten Sneep, is simply this::
     superset = [set_a, set_b]
     union = superset[Uniq(superset, Sort(superset))]
Categories
Utilities
Returns
A vector of values that are found in the combined integer sets.
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=long
   Set this keyword to a named variable containing the number of integers found in the union.
Examples
IDL> set_a = [1,2,3,4,5]
IDL> set_b = [4,5,6,7,8,9,10,11]
IDL> Print, cgSetUnion(set_a, set_b)
     1  2  3  4  5  6  7  8  9  10  11
See 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, November 25, 2009, from code originally supplied to the IDL
        newsgroup by Research Systems software engineers.
    Added COUNT keyword. 24 April 2014. DWF.
Copyright
Copyright (c) 2009-2013, Fanning Software Consulting, Inc.