Hi everybody, I have trouble solving a linear equation system with PETSc 3.0.0. I tried the following combinations of solvers and preconditioners and list the results:
cg+sor: Linear solve did not converge due to DIVERGED_NAN cg+bjacobi: Linear solve did not converge due to DIVERGED_INDEFINITE_PC cg+ilu: Linear solve did not converge due to DIVERGED_INDEFINITE_MAT gmres+sor: Linear solve did not converge due to DIVERGED_NAN gmres+bjacobi:Linear solve did not converge due to DIVERGED_ITS gmres+ilu: Linear solve did not converge due to DIVERGED_ITS It might be that the matrix is not positive definite, which explains some of the problems. In the last two cases it kind of works, but convergence is horribly slow and it aborts after 10000 iterations. If somebody could please have a look at the matrix and the right hand side vector, I've put them here: http://www.mayarea.de/download/small_matrix.tgz The archive contains a file named A.txt, consisting of three columns i j Aij and a file b.txt with two columns i and bi. Any hint on how to solve this linear equation system (in reasonable time) is appreciated. Thanks a lot in advance! Christian
