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iterative solvers
Posted:
Mar 19, 2012 3:03 PM


Hi all, I have a large matrix A (1e5,1e5), square sparse and symmetric, and I want to fine the solution of A*X=b;
X=A\b is out of question since I am running out of memory.
None of the pcg, minres or fmres algorithms converge after 250 iterations. They even gave values for x that are negative (everything should be positive).
The only think it is working for me is this file http://www.mathworks.com/matlabcentral/fileexchange/22494conjugategradientmethod
but it is painful slow. Am I doing something wrong?



