On Fri, Jul 8, 2011 at 4:17 PM, Derek Homeier <derek@astro.physik.uni-goettingen.de> wrote:

On 07.07.2011, at 7:16PM, Robert Pyle wrote:

> .............../Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/core/numeric.py:1922: RuntimeWarning: invalid value encountered in absolute
>  return all(less_equal(absolute(x-y), atol + rtol * absolute(y)))
>
>
> Everything else completes with 3 KNOWNFAILs and 1 SKIP.  This warning is not new to this release; I've seen it before but haven't  tried tracking it down until today.
>
> It arises in allclose().  The comments state "If either array contains NaN, then False is returned." but no test for NaN is done, and NaNs are indeed what cause the warning.
>
> Inserting
>
>    if any(isnan(x)) or any(isnan(y)):
>        return False
>
> before current line number 1916 in numeric.py seems to  fix it.

The same warning is still present in the current master, I just never paid attention to it because the tests still pass (it does correctly identify NaNs because they are not less_equal the tolerance), but of course this should be properly fixed as you suggest.

Under Python 2.6 I used to see this but it has disappeared. What's going on here?

$ python2.7
>>> from numpy import *
>>> absolute(nan)
__main__:1: RuntimeWarning: invalid value encountered in absolute
nan

$ python2.6
>>> from numpy import *
>>> absolute(nan)
nan

Ralf