[Numpy-discussion] Floating Point Difference between numpy and numarray

Hanni Ali hanni.ali@gmail....
Wed Sep 3 05:43:34 CDT 2008


Also can you think of a way either dtype is always float64? I have a lot of
functions and to add dtype='float64' would require *loads* of testing,
whereas if I can set it centrally on the matrix or in the environment that
would be so much easier.

Hanni


2008/9/3 Hanni Ali <hanni.ali@gmail.com>

> Sebastian you legend, that seems to be it.
>
> Thank you very much.
>
> >>> matrix.mean(dtype='float64')
> 0.41582015156745911
>
> What seems odd is that numpy doesn't do this on it's own...
>
>
>
> 2008/9/3 Sebastian Stephan Berg <sebastian@sipsolutions.net>
>
> Hi,
>>
>> just guessing here. But numarray seems to calculate the result in a
>> bigger dataype, while numpy uses float32 which is the input arrays size
>> (at least I thought so, trying it confused me right now ...). In any
>> case, maybe the difference will be gone if you
>> use .mean(dtype='float64') (or whatever dtype numarray actually uses,
>> which seems to be "numarray.MaximumType(a.type())" where a is the array
>> to take the mean).
>>
>> Sebastian
>>
>> _______________________________________________
>> Numpy-discussion mailing list
>> Numpy-discussion@scipy.org
>> http://projects.scipy.org/mailman/listinfo/numpy-discussion
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://projects.scipy.org/pipermail/numpy-discussion/attachments/20080903/496f20aa/attachment.html 


More information about the Numpy-discussion mailing list