> Anders Logg wrote: >> Question #108259 on DOLFIN changed: >> https://answers.launchpad.net/dolfin/+question/108259 >> >> Status: Open => Answered >> >> Anders Logg proposed the following answer: >> On Sat, Apr 24, 2010 at 03:38:42AM -0000, Murtazo Nazarov wrote: >> >>> New question #108259 on DOLFIN: >>> https://answers.launchpad.net/dolfin/+question/108259 >>> >>> Hi, >>> >>> My solver was working until I recompiled dolfin for some reasons. The >>> Petcs Krylov solver does not converges: >>> >>> Solving linear system of size 4184 x 4184 (PETSc Krylov solver). >>> terminate called after throwing an instance of 'std::runtime_error' >>> what(): *** Error: PETSc Krylov solver did not converge (PETSc >>> reason -4). >>> >>> However it works well with LUSolver. >>> >>> Does anyone had similar problem? >>> >> >> Are you sure it used to converge? We recently changed a warning to an >> error, so it might be that your old solver didn't converge but you >> only thought it did. >> >> > > I checked now the output of my old solver. It converged with hypre. But, > now it converges with LUSolver but not with Krylov solver. > > I simple solve the mass matrix, after applying Dirichlet boundary > conditions. > > murtazo >
I've also seen this a number of times. The problem goes away when using assemble_system that makes the matrix symmetric. I don't have a good explaination, though. And I think it is a bit strange. Kent _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
