diff --git a/packages/muelu/src/Graph/MatrixTransformation/MueLu_CoalesceDropFactory_def.hpp b/packages/muelu/src/Graph/MatrixTransformation/MueLu_CoalesceDropFactory_def.hpp index 11aa186788b3..0fd5797ac3a6 100644 --- a/packages/muelu/src/Graph/MatrixTransformation/MueLu_CoalesceDropFactory_def.hpp +++ b/packages/muelu/src/Graph/MatrixTransformation/MueLu_CoalesceDropFactory_def.hpp @@ -348,6 +348,10 @@ void CoalesceDropFactory::Build(Level } else GetOStream(Runtime0) << "algorithm = \"" << algo << "\": threshold = " << threshold << ", blocksize = " << A->GetFixedBlockSize() << std::endl; + + if (((algo == "classical") && (classicalAlgoStr.find("scaled") != std::string::npos)) || ((algo == "distance laplacian") && (distanceLaplacianAlgoStr.find("scaled") != std::string::npos))) + TEUCHOS_TEST_FOR_EXCEPTION(threshold > 1.0, Exceptions::RuntimeError, "For cut-drop algorithms, \"aggregation: drop tol\" = " << threshold << ", needs to be <= 1.0"); + Set(currentLevel, "Filtering", (threshold != STS::zero())); const typename STS::magnitudeType dirichletThreshold = STS::magnitude(as(pL.get("aggregation: Dirichlet threshold")));