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Re: IDL Question - Opposite of WHERE? [message #35455 is a reply to message #35320]

Thu, 12 June 2003 04:37

R.G. Stockwell
Messages: 363
Registered: July 1999

Senior Member

"Craig Markwardt" <craigmnet@cow.physics.wisc.edu> wrote in message
news:onvfvcrsz4.fsf@cow.physics.wisc.edu...
>
> Chad Bender <cbender@hapuna.ess.sunysb.edu> writes:
>> zygnus <suicidal_10@yahoo.com> wrote:
>> : is there a command that does the opposite of the WHERE command?
>> : Instead of returning the indeces of elements that satisfy a condition,
>> : it returns the ones that dont satisfy it
>>
>> Try using the 'COMPLEMENT' keyword with where. It should return
>> an array containing the elements not returned in the result output.
>
> Adding my tidbit:
>
> COMPLEMENT is really useful when you want to know the indices of
> *both* the true and the false values of your selection. If you just
> want the false values, then as James said, you can simply negate the
> selection expression.
>
> Craig
>
> --
> ------------------------------------------------------------ --------------
> Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
> Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
> ------------------------------------------------------------ --------------

The WHERE function is quite useful, but often I find myself really needing
a WHY function. And of course, it's opposite, the WHYNOT function.

-bob

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[Message index]

		IDL Question - Opposite of WHERE? By: suicidal_10 on Wed, 11 June 2003 15:28
		Re: IDL Question - Opposite of WHERE? By: David Fanning on Thu, 12 June 2003 07:26
		Re: IDL Question - Opposite of WHERE? By: R.G. Stockwell on Thu, 12 June 2003 04:37
		Re: IDL Question - Opposite of WHERE? By: Craig Markwardt on Wed, 11 June 2003 18:21
		Re: IDL Question - Opposite of WHERE? By: Mark Hadfield on Wed, 11 June 2003 17:25
		Re: IDL Question - Opposite of WHERE? By: Chad Bender on Wed, 11 June 2003 16:41
		Re: IDL Question - Opposite of WHERE? By: James Kuyper on Wed, 11 June 2003 15:51

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