On Tue, Feb 18, 2014 at 2:37 PM, <josef.p...@gmail.com> wrote: > On Tue, Feb 18, 2014 at 8:53 AM, Robert Kern <robert.k...@gmail.com> wrote: >> On Tue, Feb 18, 2014 at 1:46 PM, Nathaniel Smith <n...@pobox.com> wrote: >>> On 18 Feb 2014 07:07, "Robert Kern" <robert.k...@gmail.com> wrote: >>>> >>>> On Tue, Feb 18, 2014 at 12:00 PM, Nathaniel Smith <n...@pobox.com> wrote: >>>> > Perhaps integer power should raise an error on negative powers? That way >>>> > people will at least be directed to use arr ** -1.0 instead of silently >>>> > getting nonsense from arr ** -1. >>>> >>>> Controllable by np.seterr(invalid=...)? I could get behind that. >>> >>> I'm not sure the np.seterr part would work or be a good idea, given that we >>> have no way to return or propagate NaN... I vote for just an unconditional >>> error. >> >> <shrug> We issue configurable warning/error/ignore behavior for >> integer 0/0 through this mechanism too without any NaNs. However, >> that's `divide` and not `invalid`. Your point is taken that `invalid` >> usually implies that a `NaN` is generated, though I don't think this >> is ever stated anywhere. I just suggested `invalid` as that is usually >> what we use for function domain violations. > > I thought 0/0 = 0 has been removed a few versions ago. Does numpy > still have silent casting of nan to 0 in ints.
There is no casting involved. > I thought invalid and divide error/warnings are for floating point > when we want to signal that the outcome is nan or inf, not that we are > casting and return a result that is just wrong. No, they are also for some integer operations without going through a floating point intermediate. -- Robert Kern _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
