From: Wolfgang Bangerth Date: Thu, 11 Nov 2021 22:06:02 +0000 (-0700) Subject: Improve an error message. X-Git-Tag: v9.4.0-rc1~848^2 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e3be4865d0853cb137c728542cbe2175f60263d;p=dealii.git Improve an error message. --- diff --git a/source/lac/trilinos_sparse_matrix.cc b/source/lac/trilinos_sparse_matrix.cc index 1b20186c53..9c898a787e 100644 --- a/source/lac/trilinos_sparse_matrix.cc +++ b/source/lac/trilinos_sparse_matrix.cc @@ -1956,10 +1956,17 @@ namespace TrilinosWrappers const TrilinosWrappers::MPI::Vector &out) { Assert(in.trilinos_partitioner().SameAs(m.DomainMap()) == true, - ExcMessage( - "Column map of matrix does not fit with vector map!")); + ExcMessage("The column partitioning of a matrix does not match " + "the partitioning of a vector you are trying to " + "multiply it with. Are you multiplying the " + "matrix with a vector that has ghost elements?")); Assert(out.trilinos_partitioner().SameAs(m.RangeMap()) == true, - ExcMessage("Row map of matrix does not fit with vector map!")); + ExcMessage("The row partitioning of a matrix does not match " + "the partitioning of a vector you are trying to " + "put the result of a matrix-vector product in. " + "Are you trying to put the product of the " + "matrix with a vector into a vector that has " + "ghost elements?")); (void)m; (void)in; (void)out;