[Numpy-discussion] numpy.mean still broken for largefloat32arrays

Eelco Hoogendoorn hoogendoorn.eelco at gmail.com
Mon Jul 28 08:37:13 EDT 2014


To rephrase my most pressing question: may np.ones((N,2)).mean(0) and
np.ones((2,N)).mean(1) produce different results with the implementation in
the current master? If so, I think that would be very much regrettable; and
if this is a minority opinion, I do hope that at least this gets documented
in a most explicit manner.


On Sun, Jul 27, 2014 at 8:26 PM, Sturla Molden <sturla.molden at gmail.com>
wrote:

> Nathaniel Smith <njs at pobox.com> wrote:
>
> > The problem here is that when summing up the values, the sum gets
> > large enough that after rounding, x + 1 = x and the sum stops
> > increasing.
>
> Interesting. That explains why the divide-and-conquer reduction is much
> more robust.
>
> Thanks :)
>
>
> Sturla
>
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