From fd2e5e8b353965fdb3ae150ce556576c533bcd7b Mon Sep 17 00:00:00 2001
From: kronbichler <kronbichler@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Wed, 14 Jan 2009 15:18:38 +0000
Subject: [PATCH] Use CompressedSimpleSparsityPattern to create mass matrix
 sparsity pattern in project function, which uses less memory.

git-svn-id: https://svn.dealii.org/trunk@18223 0785d39b-7218-0410-832d-ea1e28bc413d
---
 .../include/numerics/vectors.templates.h      | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/deal.II/deal.II/include/numerics/vectors.templates.h b/deal.II/deal.II/include/numerics/vectors.templates.h
index c347cb5fa4..6f4616b6d3 100644
--- a/deal.II/deal.II/include/numerics/vectors.templates.h
+++ b/deal.II/deal.II/include/numerics/vectors.templates.h
@@ -19,6 +19,7 @@
 #include <lac/vector.h>
 #include <lac/block_vector.h>
 #include <lac/sparse_matrix.h>
+#include <lac/compressed_simple_sparsity_pattern.h>
 #include <lac/precondition.h>
 #include <lac/solver_cg.h>
 #include <lac/vector_memory.h>
@@ -460,12 +461,18 @@ void VectorTools::project (const Mapping<dim, spacedim>       &mapping,
 
 				   // set up mass matrix and right hand side
   Vector<double> vec (dof.n_dofs());
-  SparsityPattern sparsity(dof.n_dofs(),
-			   dof.n_dofs(),
-			   dof.max_couplings_between_dofs());
-  DoFTools::make_sparsity_pattern (dof, sparsity);
-  constraints.condense (sparsity);
-  
+  SparsityPattern sparsity;
+
+				   // use csp to consume less memory and to
+				   // still be fast
+  {
+    CompressedSimpleSparsityPattern csp (dof.n_dofs(), dof.n_dofs());
+    DoFTools::make_sparsity_pattern (dof, csp);
+    constraints.condense(csp);
+
+    sparsity.copy_from (csp);
+  }
+
   SparseMatrix<double> mass_matrix (sparsity);
   Vector<double> tmp (mass_matrix.n());
 
-- 
2.39.5