Column Product of a Matrix of zeros and 1's

*To*: mathgroup at smc.vnet.net*Subject*: [mg87957] Column Product of a Matrix of zeros and 1's*From*: P_ter <petervansummeren at gmail.com>*Date*: Mon, 21 Apr 2008 03:26:01 -0400 (EDT)

I have a matrix of zero's and ones: myGlobalMatrix; also a set called thisSet with the columns of myGlobalMatrix which have to be multiplied (e.g. column 1,3,4). I would like to know the positions of the 1's. I do this as follows: Flatten[Position[Product[myGlobalMatrix[[All,i]],{i, thisSet}],1]] But this is to general. It does not use that the matrix consists of zeros and ones. Can this be taken into account? with friendly greetings, P_ter