Re: Floating point exception when taking a reciprocal
- To: mathgroup at smc.vnet.net
- Subject: [mg110515] Re: Floating point exception when taking a reciprocal
- From: David Reiss <dbreiss at gmail.com>
- Date: Tue, 22 Jun 2010 07:00:56 -0400 (EDT)
- References: <hvn01h$q75$1@smc.vnet.net>
For Mathematica version 7 and 7.01 there is a bug in the Intel Core i7 (Nehalem) based CPU processor architecture as it is used on Linux which requires a special patched version of Mathematica to be installed. you should contact Woflram support for the patched version. --David On Jun 21, 2:15 am, Niels Walet <Niels.Wa... at manchester.ac.uk> wrote: > 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)1613064= 303 > The University of Manchester Mobile: +44(0)7905438= 934 > Manchester, M60 1QD, UK > Niels.Wa... at manchester.ac.ukhttp://theory.phy.umist.ac.uk/~mccsnrw