Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

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>