Re: [Outer [Times, , ] ] Question

*To*: mathgroup at smc.vnet.net*Subject*: [mg45803] Re: [Outer [Times, , ] ] Question*From*: bobhanlon at aol.com (Bob Hanlon)*Date*: Mon, 26 Jan 2004 01:53:08 -0500 (EST)*References*: <bv00aa$jda$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

x1 = {1, -1, -1, 1, 1}; y1 = {1, 1, -1, -1}; x2 = {-1, 1, -1, 1, -1}; y2 = {1, -1, 1, -1}; x3 = {1, 1, -1, -1, 1}; y3 = {-1, -1, 1, 1}; MatrixForm[m1=Outer [Times, x1, y1] ] MatrixForm[m2=Outer [Times, x2, y2] ] MatrixForm[m3=Outer [Times, x3, y3] ] MatrixForm[mm = m1 + m2 + m3] Or better yet, do away with all of the MatrixForm by setting your Default Output FormatType to TraditionalForm Bob Hanlon In article <bv00aa$jda$1 at smc.vnet.net>, MichaelSMcCain at cs.com wrote: << I want to take a Column Vector and multiply it by a Row Vector to create an "Outer" Matrix. In other words, I want to take a 5x1 Column Vector and multiply it by a 1x4 Row Vector and output a 5x4 Matrix. I then want to add several of these Matrices together and obtain a "final" Matrix. I tried the following: x1 = {1, -1, -1, 1, 1}; y1 = {1, 1, -1, -1}; x2 = {-1, 1, -1, 1, -1}; y2 = {1, -1, 1, -1}; x3 = {1, 1, -1, -1, 1}; y3 = {-1, -1, 1, 1}; m1 = MatrixForm[Outer [Times, x1, y1] ] m2 = MatrixForm[Outer [Times, x2, y2] ] m3 = MatrixForm[Outer [Times, x3, y3] ] mm = m1 + m2 + m3 MatrixForm[mm] The output that I get is incorrect and does not combine into a single Matrix.