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Re: ATAN inconsistencies [message #17857 is a reply to message #17729]

Mon, 15 November 1999 00:00

Michael Werger
Messages: 34
Registered: May 1997

Member

"Kenneth P. Bowman" wrote:
>
> Here's a platform dependency that took me quite a while to track down.
>
> The SGI (IRIX) version of IDL returns 0.0 when you try to take the
> arctan(0/0). The Alpha version (properly) returns a NaN.
>
> Ken Bowman
>
> IDL Version 5.1 (IRIX mipseb). Research Systems, Inc.
> IDL> print, atan(0.0, 0.0)
> 0.00000
>
> IDL Version 5.1 (OSF alpha). Research Systems, Inc.
> IDL> print, atan(0.0, 0.0)
> NaNQ
> % Program caused arithmetic error: Floating illegal operand

IDL 5.2 on Solaris 2.7:

IDL> print, atan(0.0, 0.0)
0.00000
... Any comments about the proper handling? ;-)

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Michael Werger ------------o
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[Message index]

		ATAN inconsistencies By: bowman on Fri, 12 November 1999 00:00
		Re: ATAN inconsistencies By: bowman on Mon, 15 November 1999 00:00
		Re: ATAN inconsistencies By: Michael Werger on Mon, 15 November 1999 00:00

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