MATLAB: Random Walk Matrix Optimisation

matrixoptimizationprogrammingsemidefinit

Does any one know how to perform a random walk method of optimization with matrices in MATLAB?
I have an initial matrix Q, an eigenvalue matrix L and an eigen vector V such that R=VLV'. From these I need to solve the following problem:
minimize : |Q-R| (wrt to L) such that 1. Tr(L)=a (a some constant) 2. Det(L)>0 3. R (which is VLV') is Positive semidefinite (or eigĀ®>=0)
If anyone has any clue how I can go about solving this please let me know.
Thanks, Stefan.

Best Answer

help fmincon
Best wishes
Torsten.