RE: common factors in a matrix
- To: mathgroup at smc.vnet.net
- Subject: [mg33596] RE: common factors in a matrix
- From: Bart Vorselaars <fourteen at stack.nl>
- Date: Wed, 3 Apr 2002 01:13:18 -0500 (EST)
- Organization: Eindhoven University of Technology, The Netherlands
- References: <a86ki1$jsj$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Thanks for responding to my question. The routine I use now, is a altered
version of David's FactorMatrix[mat]. This can handle any matrix (I think
:), even ones which are already 'factorized':
(*Remove common factors :*)
FactorMatrix2[(mat_)?MatrixQ] :=
Module[{contracted, flatmat, fcontracted,
prefactor, \[CapitalPsi]\[CapitalPsi]\[CapitalPsi], mult1, mult2},
contracted = 0; flatmat = Flatten[mat];
Do[contracted =
contracted +
flatmat[[ii]]*\[CapitalPsi]\[CapitalPsi]\[CapitalPsi][ii], {ii,
1,
Length[flatmat]}]; fcontracted = Factor[contracted];
If[Head[fcontracted] === Head[mult1 mult2],
prefactor = Drop[fcontracted, -1];
HoldForm @@ {prefactor}*
MatrixForm[Map[Cancel[#1/prefactor] &, mat, {2}]],
MatrixForm[mat]]]
Bart