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Re: Probs w/ keyword_set [message #2510 is a reply to message #2509]

Wed, 03 August 1994 02:03

sjt
Messages: 72
Registered: November 1993

Member

Alan Tai (tai@rockola.larc.nasa.gov) wrote:
: This is probably old news, but in IDL 3.6 (and I think in 3.51), I
: realized early on that you run into problems by setting a keyword
: parameter to 0 and running it through keyword_set. I.e. keyword_set
: believes the parameter is unset:

: pro test, Key = Key
: if (keyword_set(Key)) then print, 'Set' $
: else print, 'Unset'
: end
: test, Key = 0

: Solution: use n_elements instead of keyword_set. I found this out
: from reading through some procedures from the JHUAPL library.

This has always been the case. The main prupose of keyword_set as I've
always seen it is coupled with /<key> constructs.

: Alan

--
James Tappin, School of Physics & Space Research
University of Birmingham
sjt@xun8.sr.bham.ac.uk
"If all else fails--read the instructions!"

P.S. Did you know that keyword_set's argument needn't be a keyword! it
actually just returns 0 if arg is 0, '' or undefined and 1 otherwise.

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[Message index]

		Re: Probs w/ keyword_set By: thompson on Wed, 03 August 1994 07:09
		Re: Probs w/ keyword_set By: sjt on Wed, 03 August 1994 02:03

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