Re: Mathematica question about commutativity of multiplication

*To*: mathgroup at smc.vnet.net*Subject*: [mg96741] Re: Mathematica question about commutativity of multiplication*From*: Scott Hemphill <hemphill at hemphills.net>*Date*: Mon, 23 Feb 2009 05:03:29 -0500 (EST)*References*: <gnq6u3$89g$1@smc.vnet.net>*Reply-to*: hemphill at alumni.caltech.edu

James <james545 at gmail.com> writes: > Dear users, > > I have a 6x6 matrix in terms of > 3 variables a,b,c. That is, each entry in the matrix > is some polynomial in the variables a,b,c > with integer coefficients. > > I wish to calculate the eigenvalues of this matrix, so > if the matrix is called A, I type in Eigenvalues[A]. > > The problem is that the output is 500 pages long, so is > not useful to me. I think part of the issue is that > in my case, the variables a,b, and c commute. That is, > ab = ba, ac = ca, and bc = cb. I really believe that > if I could tell Mathematica that multiplication commutes > with my variables, then the output would be simpler. If "a" is a variable and "b" is a variable, their product is "a*b" or "a b". "ab" is just another variable unrelated to "a" and "b". Scott -- Scott Hemphill hemphill at alumni.caltech.edu "This isn't flying. This is falling, with style." -- Buzz Lightyear