# coyote: SETDEFAULTVALUE

- coyote/Utilities
- [Source code]

Description

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

Categories

      Utilities

Params

      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

      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

      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

      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 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

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