Re: Mathematica v5 versus v6

*To*: mathgroup at smc.vnet.net*Subject*: [mg80091] Re: [mg80031] Mathematica v5 versus v6*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Sun, 12 Aug 2007 07:19:05 -0400 (EDT)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <200708110603.CAA02487@smc.vnet.net>*Reply-to*: murray at math.umass.edu

Can you give us a clue as to what sort of 8-by-8 matrix you're trying to work with? I'm finding that Mathematica 6 obtains MatrixRank for RandomReal[{-10,10}] or RandomInteger[{0,100}] entries in essentially no time at all, i.e., 0. or on the order of 10^{-17}. Jon wrote: > Hi > > I have found that there are some simple problems which can be done quickly in v5 but the new v6 seemingly cannot. > > For example I am presently doing some work which requires the calculation of the Rank of an 8 by 8 matrix. Using my notebook, 1Gb RAM and 1.73GHz with v5.1, I get the answer in a few seconds. When I installed v6 and ran the same nb file I never got an answer even after running for 1 hour. > > Is there a bug in v6? > > If others are also running v6 I would be interested in getting in touch to see if other users have the same experience. If you are running on a 64 bit machine I would really like to see if that solves the problem and can give an answer with v6. > > Any comments are very welcome! > > Thanks > > Jon > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Mathematica v5 versus v6***From:*Jon <jkparry@hotmail.com>