[Numpy-discussion] Python crashes while printing a huge numpy array (Windows 1.6b2)
Charles R Harris
charlesr.harris at gmail.com
Sat Apr 23 18:59:00 EDT 2011
On Sat, Apr 23, 2011 at 4:17 PM, Christoph Gohlke <cgohlke at uci.edu> wrote:
>
>
> On 4/23/2011 2:47 PM, Charles R Harris wrote:
>
>>
>>
>> On Sat, Apr 23, 2011 at 3:38 PM, Christoph Gohlke <cgohlke at uci.edu
>> <mailto:cgohlke at uci.edu>> wrote:
>>
>>
>>
>> On 4/23/2011 10:41 AM, Charles R Harris wrote:
>> >
>> >
>> > On Sat, Apr 23, 2011 at 11:09 AM, Bruce Southey
>> <bsouthey at gmail.com <mailto:bsouthey at gmail.com>
>> > <mailto:bsouthey at gmail.com <mailto:bsouthey at gmail.com>>> wrote:
>> >
>> > On Sat, Apr 23, 2011 at 9:58 AM, Till Stensitzki
>> <mail.till at gmx.de <mailto:mail.till at gmx.de>
>> > <mailto:mail.till at gmx.de <mailto:mail.till at gmx.de>>> wrote:
>> > >
>> > > > Do you also have an earlier version of numpy installed? As David
>> > says, this
>> > > >should raise an error for recent numpy and
>> > > >I'm wondering if you are inadvertently
>> > > >running an earlier version.Chuck
>> > >
>> > >
>> > > I only have one python installation and
>> > > numpy.__version__ shows 1.6b.
>> > > I could reinstall numpy, if it would help.
>> > >
>> > > _______________________________________________
>> > > NumPy-Discussion mailing list
>> > > NumPy-Discussion at scipy.org <mailto:NumPy-Discussion at scipy.org>
>> <mailto:NumPy-Discussion at scipy.org <mailto:NumPy-Discussion at scipy.org
>> >>
>>
>> > > http://mail.scipy.org/mailman/listinfo/numpy-discussion
>> > >
>> >
>> > Hi,
>> > I can get this with 64-bit Win 7, 32-bit Python 2.6, 2.7
>> (below) and
>> > 3.1 and numpy 1.6b (fresh install) IDLE and the command line.
>> I can
>> > also confirm the 'ValueError' with Python2.6 and numpy 1.51 on
>> the
>> > same system.
>> >
>> > Actually this is 'weird' when printing and crashed with the
>> range -
>> > accessing unassigned memory?
>> > A smaller array gives an numpy error or memory error in idle.
>> >
>> > Bruce
>> >
>> >
>> > > >> import numpy as np
>> > > >> x=np.zeros((262144, 262144))
>> > > >> x
>> > array([], shape=(262144, 262144), dtype=float64)
>> > > >> x[0,0]
>> > 2.1453735050108555e-314
>> > > >> x[1:10,1:10]
>> >
>> > > >> ================================ RESTART
>> > ================================
>> > > >> import numpy as np
>> >
>> > > >> x=np.zeros((26214, 26214))
>> >
>> > Traceback (most recent call last):
>> > File "<pyshell#7>", line 1, in <module>
>> > x=np.zeros((26214, 26214))
>> > ValueError: array is too big.
>> > > >>
>> > > >> x=np.zeros((262144, 26214))
>> >
>> > Traceback (most recent call last):
>> > File "<pyshell#8>", line 1, in <module>
>> > x=np.zeros((262144, 26214))
>> > MemoryError
>> > _____
>> >
>> >
>> > This was fixed before, maybe it got broken again. Since this looks
>> > windows specific, I'm guessing it has something to do with the size
>> of
>> > long being 32 bits.
>> >
>> > The previous problem was integer overflow when multiplying the
>> > dimensions together to get the array size when repeated divisions
>> of the
>> > maximum size should have be used instead.
>> >
>> > Chuck
>>
>> Could be related to this change:
>>
>> <
>> https://github.com/numpy/numpy/commit/fcc6cc73ddcb1fc85446ba9256ac24ecdda6c6d8#L1L1121
>> >
>>
>>
>> My, that does look suspicious ;) Could you revert that loop and test it
>> out?
>>
>> There was also a function for doing that check, I don't recall which,
>> and it should probably be checked to make sure it remains as was.
>>
>> Chuck
>>
>>
>>
>
> Reverting the change worked. A patch is attached.
>
> import numpy as np
>>>> np.__version__
>>>>
>>> '1.6.0b3'
>
> x=np.zeros((262144, 262144))
>>>>
>>> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
>
> ValueError: array is too big.
>
>
Thanks, applied.
Chuck
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