On Mon, Jan 23, 2012 at 7:55 PM, David Warde-Farley <warde...@iro.umontreal.ca> wrote: > I've reproduced this (rather serious) bug myself and confirmed that it exists > in master, and as far back as 1.4.1. > > I'd really appreciate if someone could reproduce and confirm on another > machine, as so far all my testing has been on our single high-memory machine.
I see the same behaviour on a Winodows machine with numpy 1.6.1. But I don't think it is an indexing problem - rather something with the random number creation. a itself is already zeros for high indexes. In [8]: b[1000000:1000010] Out[8]: array([3429029, 1251819, 4292918, 2249483, 757620, 3977130, 3455449, 2005054, 2565207, 3114930]) In [9]: a[b[1000000:1000010]] Out[9]: array([[0, 0, 0, ..., 0, 0, 0], [0, 0, 0, ..., 0, 0, 0], [0, 0, 0, ..., 0, 0, 0], ..., [0, 0, 0, ..., 0, 0, 0], [0, 0, 0, ..., 0, 0, 0], [0, 0, 0, ..., 0, 0, 0]], dtype=uint8) In [41]: a[581350:,0].sum() Out[41]: 0 Cheers Robin > > Thanks, > David > > On Mon, Jan 23, 2012 at 05:23:28AM -0500, David Warde-Farley wrote: >> A colleague has run into this weird behaviour with NumPy 1.6.1, EPD 7.1-2, >> on Linux (Fedora Core 14) 64-bit: >> >> > a = numpy.array(numpy.random.randint(256,size=(5000000,972)),dtype='uint8') >> > b = numpy.random.randint(5000000,size=(4993210,)) >> > c = a[b] >> >> It seems c is not getting filled in full, namely: >> >> > In [14]: c[1000000:].sum() >> > Out[14]: 0 >> >> I haven't been able to reproduce this quite yet, I'll try to find a machine >> with sufficient memory tomorrow. But does anyone have any insight in the >> mean time? It smells like some kind of integer overflow bug. >> >> Thanks, >> >> David >> _______________________________________________ >> NumPy-Discussion mailing list >> NumPy-Discussion@scipy.org >> http://mail.scipy.org/mailman/listinfo/numpy-discussion > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion