From 0780605bd82d75c3d601b1e05a3e10cb4d29eb01 Mon Sep 17 00:00:00 2001 From: Matthias Maier Date: Tue, 20 Mar 2018 16:07:03 -0500 Subject: [PATCH] VectorTools: Increase max iterations in project_matrix_free Here is a funny one. Running the test numerics/project_q_hierarchical_2 with DEAL_II_NUM_THREADS=2 OMP_NUM_THREADS=2 (as done on the tester) worsens the reduction rate enough to run into the maximal iteration limit. Solve this issue by slightly increasing the maximal allowed number of iterations. --- include/deal.II/numerics/vector_tools.templates.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/deal.II/numerics/vector_tools.templates.h b/include/deal.II/numerics/vector_tools.templates.h index e4591b66e5..ca54be3b5a 100644 --- a/include/deal.II/numerics/vector_tools.templates.h +++ b/include/deal.II/numerics/vector_tools.templates.h @@ -1091,11 +1091,11 @@ namespace VectorTools } // now invert the matrix - // Allow for a maximum of 5*n steps to reduce the residual by 10^-12. n + // Allow for a maximum of 6*n steps to reduce the residual by 10^-12. n // steps may not be sufficient, since roundoff errors may accumulate for // badly conditioned matrices. This behavior can be observed, e.g. for // FE_Q_Hierarchical for degree higher than three. - ReductionControl control(5.*rhs.size(), 0., 1e-12, false, false); + ReductionControl control(6.*rhs.size(), 0., 1e-12, false, false); SolverCG > cg(control); PreconditionJacobi preconditioner; preconditioner.initialize(mass_matrix, 1.); -- 2.39.5