[Numpy-discussion] Bug in logaddexp2.reduce

josef.pktd@gmai... josef.pktd@gmai...
Thu Apr 1 00:25:02 CDT 2010


On Thu, Apr 1, 2010 at 1:22 AM,  <josef.pktd@gmail.com> wrote:
> On Thu, Apr 1, 2010 at 1:17 AM, Charles R Harris
> <charlesr.harris@gmail.com> wrote:
>>
>>
>> On Wed, Mar 31, 2010 at 6:08 PM, <josef.pktd@gmail.com> wrote:
>>>
>>> On Wed, Mar 31, 2010 at 7:37 PM, Warren Weckesser
>>> <warren.weckesser@enthought.com> wrote:
>>> > T J wrote:
>>> >> On Wed, Mar 31, 2010 at 1:21 PM, Charles R Harris
>>> >> <charlesr.harris@gmail.com> wrote:
>>> >>
>>> >>> Looks like roundoff error.
>>> >>>
>>> >>>
>>> >>
>>> >> So this is "expected" behavior?
>>> >>
>>> >> In [1]: np.logaddexp2(-1.5849625007211563, -53.584962500721154)
>>> >> Out[1]: -1.5849625007211561
>>> >>
>>> >> In [2]: np.logaddexp2(-0.5849625007211563, -53.584962500721154)
>>> >> Out[2]: nan
>>> >>
>>> >
>>> > Is any able to reproduce this?  I don't get 'nan' in either 1.4.0 or
>>> > 2.0.0.dev8313 (32 bit Mac OSX).  In an earlier email T J reported using
>>> > 1.5.0.dev8106.
>>>
>>>
>>>
>>> >>> np.logaddexp2(-0.5849625007211563, -53.584962500721154)
>>> nan
>>> >>> np.logaddexp2(-1.5849625007211563, -53.584962500721154)
>>> -1.5849625007211561
>>>
>>> >>> np.version.version
>>> '1.4.0'
>>>
>>> WindowsXP 32
>>>
>>
>> What compiler? Mingw?
>
> yes, mingw 3.4.5. , official binaries release 1.4.0 by David

sse2 Pentium M

>
> Josef
>
>>
>> Chuck
>>
>>
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>>
>>
>


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