Re: Simply but handy question

*To*: mathgroup at smc.vnet.net*Subject*: [mg124838] Re: Simply but handy question*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Thu, 9 Feb 2012 05:36:15 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201202081029.FAA06451@smc.vnet.net>*Reply-to*: murray at math.umass.edu

The question seems unclear: the purported result you show would depend on whether a, b, c were or were not 0. On 2/8/12 5:29 AM, jediwhelan wrote: > Dear group members, > > I am new to mathematica (well, I'm not actually but I haven't used it > in 5 years +). > > Is there an easy way to return a matrix X of 1's and 0's to test > whether the entries in Y > are different from zero. > > i.e., > > if Y = {{a,b},{0,c}} > > Then X would return > > X = {{1,1},{0,1}} > > This would be handy for very large or complicated matrices where one > would like to know if specific entries are zero? > > Many thanks, > Paul > -- 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**:**Simply but handy question***From:*jediwhelan <jediwhelan@googlemail.com>