Hello all,
I am trying to get X for the AX=B type of problem. I have a large banded sparse matrix A of double precision numbers. I chose GMRES as a solver. The code works with a small matrix size, but when I compile my code with a size of 4624 * 4624, i get the error bellow ,i also included the code.
% iter || residual-nrm2 || runtime || SpMV-count || info
%=================================================================================%
1 nan 0.256593 31 -202
%=================================================================================%
%=================================================================================%
% PGMRES(30) solver summary:
% initial residual: 0.000000e+00
% preconditioner setup: 0.0877 sec
% iterations: 1
% SpMV-count: 31
% exact final residual: -nan
% runtime: 0.2566 sec
% preconditioner runtime: 0.2334 sec
%=================================================================================%
Any help will be greatly appreciated.
Thanks, Ham