[Numpy-discussion] numpy.where

Robert Kern robert.kern@gmail....
Sun Jul 15 05:02:56 CDT 2007


Sebastian Haase wrote:
> On 7/14/07, Robert Kern <robert.kern@gmail.com> wrote:
>> Sebastian Haase wrote:

>>> 2) Could we have another optional argument "dtype" in numpy.where()?
>>> Otherwise I would have to always write code like this:
>>> a = N.where( arr>x, 1.0, 0.0)
>>> a = a.astype(N.float32)
>> a = N.where(arr > x, N.float32(1), N.float32(0))
> 
> If the x,y arguments are not scalars but (large) arrays this would
> need lots of unneccessary temporary memory (peak of 3 times the needed
> output memory size).
> I would wish that this function,   and others which generate output
> arrays, all get an addition optional dtype argument. (Just like the
> functions in nd-image)
> 
> Comments?

I look forward to your patch.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco


More information about the Numpy-discussion mailing list