[Numpy-discussion] Numpy.dot segmentation fault
Mark Lescroart
lescroar@usc....
Sun Jan 17 22:33:21 CST 2010
Hello,
I've encountered a segfault in numpy when trying to compute a dot
product for two arrays - see code below. The problem only seems to
occur when the arrays reach a certain size. I'm using Numpy version
1.3.0, installed via macports, on a 2.33 GHz Intel Core2 Duo Macbook
Pro running Leopard (OSX 10.5.8). I've posted this as a bug on the
numpy page, where I was told it might have to do with my ATLAS
installation (version 3.8.3_1, also installed via macports). Has
anyone run into anything like this before?
Cheers,
Mark
Example code:
import numpy as N
print 'Demonstration of Numpy Bug:'
print 'loading X (random numbers)'
SzList = [10,20,30,40,50,60,70,80,90,100]
for Sz in SzList:
print 'X size = %d,%d'%(300,Sz)
X = N.random.rand(300,Sz) Y = N.random.rand(300,3)
print 'Attempting dot product of X and Y'
N.dot(X.T,Y) print 'Finished without bug.'
Result (run through gdb):
(There were a number of warnings like this - so many that they went
off the top of the screen and I couldn't copy them all. This was
typical of the warnings.)
Reading symbols for shared libraries warning: Could not find object
file "/opt/local/var/macports/
build_opt_local_var_macports_sources_rsync
.macports.org_release_ports_lang_python26/work/Python-2.6.4/build/
temp.macosx-10.5-i386-2.6/opt/local/var/macports/
build_opt_local_var_macports_sources_rsync.macports.org_release
_ports_lang_python26/work/Python-2.6.4/Modules/_collectionsmodule.o" -
no debug information available for "/opt/local/var/macports/build/
_opt_local_var_macports_sources_rsync
.macports.org_release_ports_lang_python26/work/Python-2.6.4/Modules/
_collectionsmodule.c".
. done
Demonstration of Numpy Bug:
loading X (random numbers)
X size = 300,10
Attempting dot product of X and Y
Finished without bug.
X size = 300,20
Attempting dot product of X and Y
Finished without bug.
X size = 300,30
Attempting dot product of X and Y
Finished without bug.
X size = 300,40
Attempting dot product of X and Y
Finished without bug.
X size = 300,50
Attempting dot product of X and Y
Finished without bug.
X size = 300,60
Attempting dot product of X and Y
Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: 13 at address: 0x00000000
[Switching to process 56005 thread 0x117]
0x01038884 in ATL_dupMBmm0_2_0_b0 ()
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/numpy-discussion/attachments/20100117/06652f6d/attachment-0001.html
More information about the NumPy-Discussion
mailing list