Product command with matrices

*To*: mathgroup at smc.vnet.net*Subject*: [mg87834] Product command with matrices*From*: J Davis <texasAUtiger at gmail.com>*Date*: Fri, 18 Apr 2008 02:40:34 -0400 (EDT)

I want to define a matrix valued function such as the following (in LaTeX lingo): $$ X(0)=Id, X(n)=\prod_{i=0}^{n-1} (Id + f[i] A) $$ where A and f have already been defined and Id is the identity matrix of appropriate size. I tried the following: Id=IdentityMatrix[2]; Phi[0]:=Id; Phi[n_]:= Product[Id + f[i] A,{i,0,n-1}] However, Phi[3] and (Id+f[2]A).(Id+f[1]A).(Id+f[0]A) do not agree. Any help around this would be appreciated.

**Follow-Ups**:**Re: Product command with matrices***From:*"W_Craig Carter" <ccarter@mit.edu>

**Re: Product command with matrices***From:*Sseziwa Mukasa <mukasa@jeol.com>