[R] Optimizing variables represented in a matrix

[nataraj at orchidpharma.com]

Dear R-list members,

I have a matrix with non-numeric variables in it and I have to optimize the variables of the matrix in a formula using optim routine of the stats4 package. I know the matrix can only take numeric data and so I would like to  know how to store non-numeric variables inside a matrix.

Say for example: The 3X3 matrix is     0.05V1+V2    0.31V1        0.05V1                                                   0.31V1       0.3V1+V2      0.5V1                                          0.05V1       0.5V1         0.1V1+V2

The matrix is only for an example and the real matrix that I want to use is a 15X15 matrix ,here I would like to optimize the values of V1 and V2 using a formula.

Could you please help me how to go about to represent the matrix in R.

Thanks in advance!

B.Nataraj