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Re: SIGN function: signof(num or array of num) [message #70142]

Tue, 16 March 2010 07:01

Kenneth P. Bowman
Messages: 585
Registered: May 2000

Senior Member

In article <809h2gFboaU1@mid.individual.net>,
Carsten Lechte <chl@toppoint.de> wrote:

> F�LDY Lajos wrote:
>> I think SIGNOF() should not cause an arithmetic error for finite numbers.
>
> I use the expression
>
> (x GT 0) -1* (x LT 0)
>
> to get the sign of e.g.
>
> x = [ -2e4, 5, 0, 1d/0, -1d/0, 0d/0 ]
>
> but it uses 2 comparisons and even a multiplication. Does anyone have
> a simpler/faster version? Furthermore, what should the sign of NaN be?
>
>
> chl

ITTVIS really needs to provide a fully vectorized, tested, SIGNUM
function that can handle all the various input types.

Ken Bowman

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[Message index]

		Re: SIGN function: signof(num or array of num) By: Kenneth P. Bowman on Tue, 16 March 2010 07:01
		Re: SIGN function: signof(num or array of num) By: Carsten Lechte on Tue, 16 March 2010 06:57
		Re: SIGN function: signof(num or array of num) By: Foldy Lajos on Tue, 16 March 2010 06:31

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