Re: Re: Column Product of a Matrix of zeros and 1's

*To*: mathgroup at smc.vnet.net*Subject*: [mg88093] Re: [mg88042] Re: Column Product of a Matrix of zeros and 1's*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 24 Apr 2008 05:58:03 -0400 (EDT)*Reply-to*: hanlonr at cox.net

myM2 = {{1, 1, 0, 0, 0, 0, 1, 0, 0}, {1, 1, 0, 0, 0, 0, 1, 1, 0}, {1, 1, 1, 0, 0, 0, 1, 1, 0}, {1, 0, 1, 0, 0, 0, 1, 1, 1}, {1, 1, 0, 1, 0, 1, 0, 0, 0}, {1, 1, 1, 1, 0, 1, 0, 0, 0}, {1, 0, 1, 1, 1, 0, 0, 0, 0}, {1, 0, 1, 1, 0, 1, 0, 0, 0}}; thisSet = {1, 2}; Flatten[Position[Times @@ Transpose[myM2][[thisSet]], 1]] {1,2,3,5,6} Intersection @@ (Flatten[Position[#, 1]] & /@ Transpose[myM2][[thisSet]]) {1,2,3,5,6} Bob Hanlon ---- P_ter <petervansummeren at gmail.com> wrote: > Hello Bill, > thanks for your answer and sorry I am not clear. This is an example of myGlobalMatrix: > myM2 = { > {1, 1, 0, 0, 0, 0, 1, 0, 0}, > {1, 1, 0, 0, 0, 0, 1, 1, 0}, > {1, 1, 1, 0, 0, 0, 1, 1, 0}, > {1, 0, 1, 0, 0, 0, 1, 1, 1}, > {1, 1, 0, 1, 0, 1, 0, 0, 0}, > {1, 1, 1, 1, 0, 1, 0, 0, 0}, > {1, 0, 1, 1, 1, 0, 0, 0, 0}, > {1, 0, 1, 1, 0, 1, 0, 0, 0} > }; > I take the product of colomn 1 and 2 as an example: > {1,1,1,0,1,1,0,0} (thisSet= {1,2}) > The positions of the 1's are: {1,2,3,5,6} (with Flatten) > I solved how to do this for thisSet etc. But I did not use the property that myGlobalMatrix (myM2)is 1's and 0's. > > with friendly greetings, > P_ter >