matrix equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg109590] matrix equation*From*: "Conlon, Paul" <Paul.Conlon at xerox.com>*Date*: Fri, 7 May 2010 06:28:48 -0400 (EDT)

Hi & thanks. Here is my problem: Similarity matrix equation: A . B == == B . C If I have A and C, how do I determine B? I've looked at Solve and eigenvalues, etc. and have limited success with Solve (can accurately get a several of the matrix element, but not all. Eg seems I can get sort of parametric response when I put in B where I have the elements ....{{m11, m12, ...}, {m21, m22,....}, ...} ). Surely there is a solution because I can create A,B,C that work. But sometimes I get elements that are the trivial solution (zeroes). Also, this is for a real world app, so the elements are real. I looked at Solve, SolveAlways, FindInstance and the other recommended fns. If it is parametric, interesting, but since I get some correct values from real-world (vs real - ha) matrices I am dealing with that seems less likely. Thanks. Paul