Re: Floating point exception when taking a reciprocal
- To: mathgroup at smc.vnet.net
- Subject: [mg110490] Re: Floating point exception when taking a reciprocal
- From: Niels Walet <Niels.Walet at manchester.ac.uk>
- Date: Mon, 21 Jun 2010 02:10:13 -0400 (EDT)
Leo Alekseyev wrote: > I am running into a strange bug where taking reciprocals of a list of > floating point numbers crashes the kernel with a floating point > exception. This is on a Linux x86_64 system, Ubuntu 9.10, running > Mathematica 7.0.1.0 > > Something like > foo=Array[1.0&,1000]; 1/foo > or > foo=RandomReal/@Range[100]; 1/foo > gives me the crash > Replacing floats with integers makes things work fine, also, for small > enough lists (order of 10 elements) everything works. > > Same version of Mathematica on a 32-bit linux system or on Windows > doesn't exhibit this behavior. > > I am rather mystified by what's going on; my hardware/OS is pretty > standard, so if the bug were this obvious it would have long been > known by now... But if anyone else has run into similar behavior > and/or knows of some sort of a fix, please let me know. > > Thanks, > > --Leo > > I have seen similar problems (with Scientific linux 5 64 bits on an intel i5 processor). The same code works on the identical OS with an older Core2 processor. I have the feeling it is due to the issue with the intel math library for i7 (http://support.wolfram.com/technotes/IntelCorei7.html), but am not sure, since I can't directly talk to wolfram (site license). -- Prof. Niels R. Walet Phone: +44(0)1613063693 School of Physics and Astronomy Fax: +44(0)1613064303 The University of Manchester Mobile: +44(0)7905438934 Manchester, M60 1QD, UK Niels.Walet at manchester.ac.uk http://theory.phy.umist.ac.uk/~mccsnrw