Problem introduced after 1.0rc2 on AIX with xlc

Brian Granger ellisonbg.net at gmail.com
Sat Oct 21 00:01:42 CDT 2006


Thanks, I will investigate more on these things and get back to you
early in the week.  But for now numpy seems to be functioning pretty
normally (log(2) gives the correct answer).  thanks again.
It would be great to figure this stuff out before 1.0, but we might
not have time.


Brian

On 10/20/06, Tim Hochberg <tim.hochberg at ieee.org> wrote:
> Brian Granger wrote:
> > When I set seterr(all='warn') I see the following:
> >
> > In [1]: import numpy
> > /usr/common/homes/g/granger/usr/local/lib/python/numpy/lib/ufunclike.py:46:
> > RuntimeWarning: invalid value encountered in log
> >   _log2 = umath.log(2)
> > /usr/common/homes/g/granger/usr/local/lib/python/numpy/lib/scimath.py:19:
> > RuntimeWarning: invalid value encountered in log
> >   _ln2 = nx.log(2.0)
> >
> [etc, etc]
>
> Wow! That looks pretty bad. What do you get if you try just
> "numpy.log(2)" or "numpy.log(2.0)"? Is it producing sane results for
> scalars at all? I suppose another possibility is that the error
> reporting is broken on AIX for some reason.
>
> Hmmm.
>
> I'm betting that is is. The macro UFUNC_CHECK_STATUS is very platform
> dependent. There is a version from AIX (ufuncobject.h line 301), but
> perhaps it's broken on your particular configuration and as a result is
> spitting out all kinds of bogus errors. This is only coming to light now
> because the default error checking level got cranked up.
>
> I gotta call it a night and I'll be out tomorrow, so I won't be much
> more help, but here's something that you might look into: have you
> compiled numarray sucessfully? If you haven't you might want to try it.
> It uses the same default error checking that numpy is now using. If you
> have, you might want to look for the equivalent of UFUNC_CHECK_STATUS
> (it might even have the same name) and splice it into numpy and see if
> it fixes your problems.
>
> Of course, if numpy.log(2) is spitting out something bogus, there's
> something much worse going on, but I suspect you would have noticed that
> by now.
>
> Good luck,
>
> -tim
>
>
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