From: Kirk, Benjamin (JSCEG) <Benjamin.K<irk1@na...>  20090113 23:19:40

The easiest answer is to use a petsc command line option snes_max_it # I believe (help will tell you all the options for the particular petsc functions you are using) . Longer term, we will look into using the provided option properly. Ben  Original Message  From: yunfei zhu <yzhu2009@...> To: libmeshusers@... <libmeshusers@...> Sent: Tue Jan 13 16:23:23 2009 Subject: [Libmeshusers] nonlinear steps Hi, all I find that the number of nonlinear steps can not be controled by: es.parameters.set<unsigned int> ("nonlinear solver maximum iterations") = 100 In the function NonlinearImplicitSystem::solve ( ) , the parameter is assigned to "maxits" by: const unsigned int maxits = es.parameters.get<unsigned int>("nonlinear solver maximum iterations"); Then "maxits" is transfered to nonlinear_solver: const std::pair<unsigned int, Real> rval = nonlinear_solver>solve (*matrix, *solution, *rhs, rel_resid_tol, maxits); I have checked the file of petsc_nonlinear_solver.C, actually, the "maxits" is not adopted in the following function: template<typename T > std::pair< unsigned int, Real > PetscNonlinearSolver< T >::solve ( SparseMatrix< T > & jac_in, NumericVector< T > & x_in, NumericVector< T > & r_in, const double, const unsigned int ) . I just tried to make add the following in the function PetscNonlinearSolver< T >::solve() before ierr = SNESSolve (_snes, PETSC_NULL, x>vec()); CHKERRABORT(libMesh::COMM_WORLD,ierr); EquationSystems& es = this>system().get_equation_systems(); int maxFails = es.parameters.get<unsigned int>("maxFails"); ierr = SNESSetMaximumUnsuccessfulSteps(_snes,maxFails); CHKERRABORT(libMesh::COMM_WORLD,ierr); But it does not work. I am a beginner for C++, so maybe this question is stupid. But I really do not know how to solve it. Controlling the NL steps is important for my nonlinear PDEs. Could anyone give me some suggestion? Thanks in advance. With best wishes, yunfei  This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sfspreadtheword _______________________________________________ Libmeshusers mailing list Libmeshusers@... https://lists.sourceforge.net/lists/listinfo/libmeshusers 