[Numpy-discussion] What is the sign of nan?

Nathan Bell wnbell@gmail....
Tue Sep 30 00:46:43 CDT 2008


On Tue, Sep 30, 2008 at 1:20 AM, Robert Kern <robert.kern@gmail.com> wrote:
>
> F.9.9.2 The fmax functions
> 1 If just one argument is a NaN, the fmax functions return the other
> argument (if both arguments are NaNs, the functions return a NaN).
> 2 The body of the fmax function might be
> {return (isgreaterequal(x, y) ||
>  isnan(y)) ? x : y; }
>
> If we want to follow C99 semantics rather than our own
> NaN-always-propagates semantics, then we should do this instead.
>

+1 for NaN-always-propagates since we have explicit variants for the
alternative semantics.

Users are more likely to remember that "NaNs always propagate" than
"as stated in the C99 standard...".

-- 
Nathan Bell wnbell@gmail.com
http://graphics.cs.uiuc.edu/~wnbell/


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