[Numpy-discussion] float96 on windows32 is float64?

Val Kalatsky kalatsky at gmail.com
Fri Mar 16 00:33:49 EDT 2012


I just happened to have an xp64 VM running:
My version of numpy (1.6.1) does not have float128 (see more below what I
get in ipython session).
If you need to test something else please let me know.
Val
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Welcome to pylab, a matplotlib-based Python environment [backend: WXAgg].
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In [1]: import numpy as np

In [2]: np.__version__
Out[2]: '1.6.1'

In [3]: np.flo
np.float        np.float32      np.float_       np.floor
np.float16      np.float64      np.floating     np.floor_divide

In [3]: np.flo

On Thu, Mar 15, 2012 at 11:25 PM, Matthew Brett <matthew.brett at gmail.com>wrote:

> Hi,
>
> On Thu, Mar 15, 2012 at 9:17 PM, David Cournapeau <cournape at gmail.com>
> wrote:
> >
> >
> > On Thu, Mar 15, 2012 at 11:10 PM, Matthew Brett <matthew.brett at gmail.com
> >
> > wrote:
> >>
> >> Hi,
> >>
> >> Am I right in thinking that float96 on windows 32 bit is a float64
> >> padded to 96 bits?
> >
> >
> > Yes
> >
> >>
> >>  If so, is it useful?
> >
> >
> > Yes: this is what allows you to use dtype to parse complex binary files
> > directly in numpy without having to care so much about those details. And
> > that's how it is defined on windows in any case (C standard only forces
> you
> > to have sizeof(long double) >= sizeof(double)).
>
> I propose then to rename this one to float64_96 .
>
> The nexp value in finfo(np.float96) is incorrect I believe, I'll make
> a ticket for it.
>
> >>  Has anyone got a windows64
> >> box to check float128 ?
> >
> >
> > Too lazy to check on my vm, but I am pretty sure it is 16 bytes on
> windows
> > 64.
>
> Should you have time to do that, could you confirm it's also a padded
> float64 and that nexp is still (incorrectly) 15?   That would be a
> great help,
>
> Thanks,
>
> Matthew
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