From bd4887530154908713a349bb963749babf9247f1 Mon Sep 17 00:00:00 2001
From: Thomas Witkowski <thomas.witkowski@gmx.de>
Date: Mon, 20 Feb 2012 13:25:41 +0000
Subject: [PATCH] Possibility to remove null space of rhs vectors in parallel
computations.
---
AMDiS/src/parallel/PetscSolverGlobalMatrix.cc | 7 +++++++
AMDiS/src/parallel/PetscSolverGlobalMatrix.h | 8 +++++++-
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc b/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc
index cd21ab43..5c9562aa 100644
--- a/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc
+++ b/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc
@@ -151,6 +151,13 @@ namespace AMDiS {
VecAssemblyBegin(petscRhsVec);
VecAssemblyEnd(petscRhsVec);
+
+ if (removeRhsNullSpace) {
+ MatNullSpace sp;
+ MatNullSpaceCreate(PETSC_COMM_WORLD, PETSC_TRUE, 0, PETSC_NULL, &sp);
+ MatNullSpaceRemove(sp, petscRhsVec, PETSC_NULL);
+ MatNullSpaceDestroy(&sp);
+ }
}
diff --git a/AMDiS/src/parallel/PetscSolverGlobalMatrix.h b/AMDiS/src/parallel/PetscSolverGlobalMatrix.h
index e53add03..4e60a933 100644
--- a/AMDiS/src/parallel/PetscSolverGlobalMatrix.h
+++ b/AMDiS/src/parallel/PetscSolverGlobalMatrix.h
@@ -88,11 +88,14 @@ namespace AMDiS {
o_nnz(NULL),
lastMeshNnz(0),
zeroStartVector(false),
- alwaysCreateNnzStructure(false)
+ alwaysCreateNnzStructure(false),
+ removeRhsNullSpace(false)
{
Parameters::get("parallel->use zero start vector", zeroStartVector);
Parameters::get("parallel->always create nnz structure",
alwaysCreateNnzStructure);
+ Parameters::get("parallel->remove rhs null space",
+ removeRhsNullSpace);
}
void fillPetscMatrix(Matrix<DOFMatrix*> *mat);
@@ -141,6 +144,9 @@ namespace AMDiS {
/// Mapping from global DOF indices to global matrix indices under
/// consideration of possibly multiple components.
DofToMatIndex dofToMatIndex;
+
+ /// If true, the constant null space is projected out of the RHS vector.
+ bool removeRhsNullSpace;
};
--
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