RE: column * row ??

*To*: mathgroup at smc.vnet.net*Subject*: [mg28812] RE: [mg28791] column * row ??*From*: "David Park" <djmp at earthlink.net>*Date*: Mon, 14 May 2001 01:33:03 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

John, colvec = {a1, a2, a3}; rowvec = {b1, b2, b3}; Transpose[{colvec}].{rowvec} {{a1 b1, a1 b2, a1 b3}, {a2 b1, a2 b2, a2 b3}, {a3 b1, a3 b2, a3 b3}} But probably the more Mathematica way of doing it would be... Outer[#1 #2 &, colvec, rowvec] {{a1 b1, a1 b2, a1 b3}, {a2 b1, a2 b2, a2 b3}, {a3 b1, a3 b2, a3 b3}} David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ > From: J.R. Chaffer [mailto:jrchaff at mcn.net] To: mathgroup at smc.vnet.net > > Hi there, > > Can someone tell me a way to mimic the building of > an N x N matrix by multiplying a column vector > on left times a row vector on right ? (both vectors > of length N) - I mean in Mathematica, of course. > > i.e, want the result, > > (colvec){a1,a2, .. aN} * (rowvec){b1,b2,..bN} = > > result is matrix: > > {{a1*b1 a1*b2 ..... a1*bN}, > {a2*b1 a2*b2 ..... a2*bN}, > ... ... ... , > {aN*b1 aN*b2 ..... aN*bN}} > > > When I try this in Mathematica all I can figure out > how to produce is the standard dot-product. If I > try the 'transposed' lists/matrices, I get an error, > even tho the product is defined by basic rules of > matrix multiplication. > > Thanks, > > John Chaffer >

**Follow-Ups**:**Re: RE: column * row ??***From:*Raul Martinez <rmartinez@vrinc.com>