I have a sparse, structurally-symmetric matrix. The solution of this matrix is part of a larger iterative solver, so the matrix needs to be solved many times. The values in the matrix will modestly change between iterations, but the sparsity pattern will remain the same.
Based on my reading of the PARDISO documentation, it sounds like this situation argues strongly for the implementation of the CGS iterative scheme. It sounds like PARDISO needs to be called once with phase=11, and then subsequently called with phase=23 and iparm(4)=31. Is this correct? I havent been able to get this to work. I get the following errors:
*** Error in PARDISO ( numerical_factorization) error_num= -3