Re: How to make a loop for this problem!

*To*: mathgroup at smc.vnet.net*Subject*: [mg75382] Re: How to make a loop for this problem!*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Fri, 27 Apr 2007 05:27:38 -0400 (EDT)*Organization*: The Open University, Milton Keynes, UK*References*: <f0pkt5$28h$1@smc.vnet.net>

pskmaths at googlemail.com wrote: > Hi all, > > This comand: > A = Array[Random[Integer] &, {3, 3}] > generates a 3x3 random matrix its terms between 0 and 1. > > I need to make a loop that geerates a finite number of matrices, let's > say 512 and this loop check that non of the matrices is equal to > another one (no repeated matrices) > > I can geerate thoses random, matrices with this command: > Do[Print[Array[Random[Integer] &, {3, 3}]], {512}] > but I may have two matrices that are equal and also as far as I know I > cann't use the out put because of the command, Print. Here is a functional approach to solve your problem. matArray contains the whole set (512 elements) of 3 by 3 matrices made of entries either 0 or 1. Then, you can access any element of the list with one or more indices, either fixed or randomly generated. In[1]:= matArray = (Partition[#1, 3] & ) /@ Tuples[{0, 1}, 9]; matArray[[15]] matArray[[Table[Random[Integer, {1, 512}], {2}]]] Out[2]= {{0, 0, 0}, {0, 0, 1}, {1, 1, 0}} Out[3]= {{{0, 0, 0}, {1, 0, 1}, {1, 0, 1}}, {{0, 1, 1}, {0, 1, 1}, {1, 1, 1}}} Regards, Jean-Marc