On Mon, Jun 13, 2016 at 11:51 AM, <josef.p...@gmail.com> wrote:
>
>
> On Mon, Jun 13, 2016 at 11:25 AM, Antoine Pitrou <solip...@pitrou.net>
> wrote:
>
>> On Mon, 13 Jun 2016 10:49:44 -0400
>> josef.p...@gmail.com wrote:
>> >
>> > My argument is that `**` is like integer division and sqrt where the
>> domain
>> > where integer return are the correct numbers is too small to avoid
>> > headaches by users.
>>
>> float64 has less integer precision than int64:
>>
>> >>> math.pow(3, 39) == 3**39
>> False
>> >>> np.int64(3)**39 == 3**39
>> True
>>
>
> but if a user does this, then ??? (headaches or head scratching)
>
> >>> np.array([3])**39
> RuntimeWarning: invalid value encountered in power
>
> array([-2147483648], dtype=int32)
>
I forgot to add
the real headaches start in the second call, when we don't get the
RuntimeWarning anymore
>>> np.array([4])**39
array([-2147483648], dtype=int32)
("Now, why do I owe so much money, when I made a huge profit all year." )
Josef
>
> Josef
>
>
>>
>>
>> (as a sidenote, np.float64's equality operator seems to be slightly
>> broken:
>>
>> >>> np.float64(3)**39 == 3**39
>> True
>> >>> int(np.float64(3)**39) == 3**39
>> False
>> >>> float(np.float64(3)**39) == 3**39
>> False
>> )
>>
>> Regards
>>
>> Antoine.
>>
>>
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>>
>
>
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