[Numpy-discussion] np.dtype(int) 64bit

Peter Butterworth butterw@gmail....
Sun Oct 24 03:41:54 CDT 2010


thanks for the clarification.

I haven't found any complete guide on the subject, but it does appear
there are a some potential gotchas with using numpy 64bit on windows
(result type is not what the user might expect).

>>> np.shape([1, 5, 4])
(3L,)

Is there a clear performance advantage for numpy 64bit over numpy
32bit on 64 bit windows ? I might be tempted to go back to 32bit
python to


<quote author="Christoph Gohlke">

Looks correct. CPython's 'int' is implemented as 'long' in C, which is
32 bit on Windows (LLP64 model) and 64 bit on other systems (LP64, etc).
The function argmin() returns an index, which is implemented as
'Py_ssize_t' in C and is 64 bit on all 64 bit systems.

--
Christoph
</quote>

-- 
thanks,
peter butterworth


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