This procedure sets default values for positional and keyword arguments to IDL procedures and functions.
Utilities
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.
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].
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
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
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 (c) 2008-2014, Fanning Software Consulting, Inc.