[Numpy-discussion] Bug in logaddexp2.reduce

[josef.pktd at gmail.com]

On Thu, Apr 1, 2010 at 1:17 AM, Charles R Harris
<charlesr.harris at gmail.com> wrote:
>
>
> On Wed, Mar 31, 2010 at 6:08 PM, <josef.pktd at gmail.com> wrote:
>>
>> On Wed, Mar 31, 2010 at 7:37 PM, Warren Weckesser
>> <warren.weckesser at enthought.com> wrote:
>> > T J wrote:
>> >> On Wed, Mar 31, 2010 at 1:21 PM, Charles R Harris
>> >> <charlesr.harris at 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

Josef

>
> Chuck
>
>
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