Re: Question: getting list data into a matrix
- To: mathgroup at smc.vnet.net
- Subject: [mg17260] Re: Question: getting list data into a matrix
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Fri, 30 Apr 1999 02:34:44 -0400
- Organization: Universitaet Leipzig
- References: <7g0smo$dv9@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Ben,
MakeMatrix[l:{_Equal..},vec_List]:=
Module[{eqns,m,b},
eqns=l /. a_==b_ /; b!=0 :> a-b;
m=Outer[D[#1,#2] &,eqns ,vec];
b= m.vec-eqns;
{m,b}
]
will return a list of the matrix of the linear system and the
right-hand side vector. If you call it with the list of linear
equations and the vector of unkowns
Hope that helps
Jens
Ben Johnson wrote:
>
> I'm trying to convert some equations from a list into a matrix to solve.
>
> The data is in a list that looks like this:
>
> {2 a[1]+3 b[1]+4 c[1]==0, 2 a[2]+4b[6]==24} etc.
>
> Any help would be appreciated. Please reply to bdjohns1 at uiuc.edu - my
> header address will work, but it's a spam-trap.
>
> Thanks in advance for any help.
>
> --
> Ben Johnson
> bdjohns1-usenet at uiuc.edu
> (remove -usenet to reply)