[Python-Dev] RE: Possible bug (was Re: numpy, overflow, inf, ieee, and rich comparison)

Thomas Wouters thomas@xs4all.net
Thu, 12 Oct 2000 10:11:57 +0200

On Wed, Oct 11, 2000 at 10:44:20PM -0400, Tim Peters wrote:

> > Likewise sqrt(-1.) needs to stop, not put a zero and keep going.

> Nobody has proposed changing anything about libm domain (as opposed to
> range) errors (although Huaiyu probably should if he's serious about his
> flavor of 754 subsetism -- I have no idea what gcc+glibc+Linux did here on
> 1.5.2, but it *should* have silently returned a NaN (not a zero) without
> setting errno if it was *self*-consistent -- anyone care to check that
> under -lieee?:

>     import math
>     math.sqrt(-1)

>>> import math
>>> math.sqrt(-1)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
OverflowError: math range error

The same under both 1.5.2 and 2.0c1 with -lieee. Without -lieee, both do:

>>> import math
>>> math.sqrt(-1)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
ValueError: math domain error

Consistency-conschmistency-ly y'rs,

Thomas Wouters <thomas@xs4all.net>

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