[Numpy-discussion] invalid numeric result(s) in divide

[Warren Focke]

On Fri, 13 Aug 2004, Curzio Basso wrote:

>  >>> tmp = NA.where(w > 0.0, tmp / w, 0.0)
> Warning: Encountered invalid numeric result(s)  in divide
>
> Ah, both matrices have no 'nan' or 'inf' elements. So, where could the
> invalid result come from?

All of the arguments to NA.where are evaluated before the function is
called, so tmp/w results in divide-by-zero.  The array that gets passed to
NA.where contains some inf or nan (I suspect the latter based on the
warning message), but you don't see them in the return value because
NA.where replaces them w/ 0.

Warren Focke