[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.


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
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