[petsc-users] minres: PETSc&MATLAB

Umut Tabak u.tabak at tudelft.nl
Wed Apr 7 17:58:32 CDT 2010

Dear all,

I have tried on some ill-conditioned(indefinite actually) matrices some 
iterative solutions first with minres of Matlab. Matlab converged in 
something like 30 iterations to some reasonable tolerances, say 1e-5, 
without any preconditioner. However, the same matrices did not converge 
with the minres solver of PETSc. I wondered what could be the 
differences in implementation? I would expect PETSc to perform better, 
no supporting arguments for this expectation though.

I read the matrices in binary format, and use on the command line(with 
some modifications on the ex1.c code)

./ex1 -ksp_type minres -pc_type none

Best regards,


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