Converting set of equations to matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg26709] Converting set of equations to matrix*From*: Helge Kreutzmann <helgek at studserv.stud.uni-hannover.de>*Date*: Thu, 18 Jan 2001 00:57:15 -0500 (EST)*Organization*: Universitaet Hannover*Sender*: owner-wri-mathgroup at wolfram.com

Hello ! I have a set of equations I create following some rules, like 3 a[0,0] + 2 a[0,2] + 4 a[2,0] = 0 -1 a[0,0] + 0.3 a[2,0] = 0 4 a[0,2] - 1 a[0,2] = 0 The numbers of coefficients (the a[i,j]) is different in each run but fixed. For further calculations I would like to transform the above equations into the matrix {{3,2,4 },{-1,0,0.3},{0,4,-1}} Currently I have a list (called coeffli) where I can get the equations from. The existing coefficients are stored in a second list (klist). I also have a list where the values i,j are stored (cplist). The above list I would create by For[i = 1, i <= Length[kflist], i++, Print[Collect[coeffli[[cplist[[i]][[1]]]][[cplist[[i]][[2]]]], klist]]] I can create a list of the equations but I do not know how to tear apart the sum into matrix elements. Thanks Helge

**Follow-Ups**:**Re: Converting set of equations to matrix***From:*Daniel Lichtblau <danl@wolfram.com>