[Numpy-discussion] please change mean to use dtype=float

Sebastian Haase haase at msg.ucsf.edu
Tue Sep 19 18:59:08 CDT 2006


On Tuesday 19 September 2006 15:48, Travis Oliphant wrote:
> Sebastian Haase wrote:
<snip>
> >can we please change dtype to default to float64 !?
>
> The default is float64 now (as long as you are not using
> numpy.oldnumeric).
>
> I suppose more appropriately, we could reduce over float for integer
> data-types when calculating the mean as well (since a floating point is
> returned anyway).
>

Is now mean() always "reducing over" float64 ? 
The svn note """Log:
Fix mean, std, and var methods so that they reduce over double data-type with 
integer inputs.
"""
makes it sound that a float32 input is stays float32 ?

For mean calculation this might introduce large errors - I usually would 
require double-precision for *any*  input type ...

(don't know how to say this for complex types !? Are here real and imag 
treated separately / independently ?)

Thanks,
Sebastian Haase




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