This procedure sets default values for positional and keyword arguments to
  IDL procedures and functions.

Categories

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    Utilities

Params

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    argument: in, required
        The augument variable you are setting the default value of. If this variable
        is undefined, the `defaultValue` will be assigned to it. Otherwise, the argument
        variable will not change.
    defaultvalue: in, required
        The default value that will be assigned to the argument variable ONLY if the argument
        variable is undefined. If this variable is undefined, the argument variable will
        be treated as if the BOOLEAN keyword had been set.

Keywords

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    boolean: in, optional, type=integer
        If this keyword is set, the argument value will always be forced to return with a
        value of 0 or 1.
    range: in, optional
        A two-element array that gives the accepted range of the variable. The output argument
        will be forced into this data range: range[0] > argument < range[1].

Examples

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    Here is how to use this program::
   
      FUNCTION Action, arg1, arg2, MULTIPLY=multiply
 
        SetDefaultValue, arg1, 1
        SetDefaultValue, arg2, 2
        SetDefaultValue, multiply, 1, /BOOLEAN
   
        IF multiply THEN RETURN, arg1 * arg2 ELSE RETURN, arg1 + arg2
   
      END

Author

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    FANNING SOFTWARE CONSULTING::
      David W. Fanning
      1645 Sheely Drive
      Fort Collins, CO 80526 USA
      Phone: 970-221-0438
      E-mail: [email protected]
      Coyote's Guide to IDL Programming: http://www.idlcoyote.com

History

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    Change History::
        Written by: David W. Fanning, November 26, 2008, from suggestion by Carsten Lechte on
          IDL newsgroup on this date.
        Made a change to the way the BOOLEAN keyword works. Now argument is set to BOOLEAN before
          return, if required. 3 Dec 2008. DWF.
        Added RANGE keyword. 22 March 2014. DWF.

Copyright

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    Copyright (c) 2008-2014, Fanning Software Consulting, Inc.