From: wolf <wolf@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Mon, 31 Jan 2000 15:43:31 +0000 (+0000)
Subject: Single out the function that computes the inverses in a first step to parallelize... 
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f5498a7dcacebf77375c6024006ead91a731a364;p=dealii-svn.git

Single out the function that computes the inverses in a first step to parallelize the creation of the inverses.


git-svn-id: https://svn.dealii.org/trunk@2295 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/lac/include/lac/sparse_vanka.h b/deal.II/lac/include/lac/sparse_vanka.h
index 718f47fa2a..c33ae98435 100644
--- a/deal.II/lac/include/lac/sparse_vanka.h
+++ b/deal.II/lac/include/lac/sparse_vanka.h
@@ -11,6 +11,7 @@
 #include <lac/forward_declarations.h>
 
 #include <vector>
+#include <map>
 
 
 /**
@@ -203,6 +204,23 @@ class SparseVanka
 				      * selected diagonal elements.
 				      */
     void compute_inverses ();
+
+				     /**
+				      * Compute the inverse of the
+				      * block located at position
+				      * #row#. Since the map is used
+				      * quite often, it is generated
+				      * only once in the caller of
+				      * this function and passed to
+				      * this function which first
+				      * clears it. Reusing the map
+				      * makes the process
+				      * significantly faster than in
+				      * the case where this function
+				      * re-creates it each time.
+				      */
+    void compute_inverse (const unsigned int               row,
+			  map<unsigned int, unsigned int> &local_index);
 };
 
 
diff --git a/deal.II/lac/include/lac/sparse_vanka.templates.h b/deal.II/lac/include/lac/sparse_vanka.templates.h
index 8ed7e4e1ea..71f97593ca 100644
--- a/deal.II/lac/include/lac/sparse_vanka.templates.h
+++ b/deal.II/lac/include/lac/sparse_vanka.templates.h
@@ -46,82 +46,91 @@ template <typename number>
 void
 SparseVanka<number>::compute_inverses () 
 {
-				   // first define an alias to the sparsity
-				   // pattern of the matrix, since this
-				   // will be used quite often
-  const SparsityPattern &structure
-    = matrix->get_sparsity_pattern();
-
   map<unsigned int, unsigned int> local_index;
 
 				   // traverse all rows of the matrix
 				   // which are selected
   for (unsigned int row=0; row< matrix->m() ; ++row)
     if (selected[row] == true)
-      {
-	const unsigned int row_length = structure.row_length(row);
-	inverses[row] = new FullMatrix<float> (row_length,
-					       row_length); 
-					 // mapping between:
-					 // 1 column number of all
-					 //   entries in this row, and
-					 // 2 the position within this
-					 //   row (as stored in the
-					 //   SparsityPattern object
-					 //
-					 // since we do not explicitely
-					 // consider nonsysmmetric sparsity
-					 // patterns, the first element
-					 // of each entry simply denotes
-					 // all degrees of freedom that
-					 // couple with #row#.
-	local_index.clear ();
-	for (unsigned int i=0; i<row_length; ++i)
-	  local_index.insert(pair<unsigned int, unsigned int>
-			     (structure.column_number(row, i), i));
-	
-					 // Build local matrix and rhs
-	for (map<unsigned int, unsigned int>::const_iterator is=local_index.begin();
-	     is!=local_index.end(); ++is)
-	  {
-					     // irow loops over all DoFs that
-					     // couple with the present DoF
-	    const unsigned int irow = is->first;
-					     // index of DoF irow in the matrix
-					     // row corresponding to DoF #row#.
-					     // runs between 0 and row_length
-	    const unsigned int i = is->second;
-					     // number of DoFs coupling to
-					     // irow (including irow itself)
-	    const unsigned int irow_length = structure.row_length(irow);
-	    
-					     // for all the DoFs that irow
-					     // couples with
-	    for (unsigned int j=0; j<irow_length; ++j)
-	      {
-						 // col is the number of
-						 // this dof
-		const unsigned int col = structure.column_number(irow, j);
-						 // find out whether this DoF
-						 // (that couples with #irow#,
-						 // which itself couples with
-						 // #row#) also couples with
-						 // #row#.
-		const map<unsigned int, unsigned int>::const_iterator js
-		  = local_index.find(col);
+      compute_inverse (row, local_index);
+};
 
-		if (js != local_index.end())
-		  (*inverses[row])(i,js->second) = matrix->raw_entry(irow,j);
-	      };
-	  };
-	
-					 // Compute new values
-	inverses[row]->gauss_jordan();
-      };
+
+
+template <typename number>
+void
+SparseVanka<number>::compute_inverse (const unsigned int               row,
+				      map<unsigned int, unsigned int> &local_index) 
+{
+				   // first define an alias to the sparsity
+				   // pattern of the matrix, since this
+				   // will be used quite often
+  const SparsityPattern &structure
+    = matrix->get_sparsity_pattern();
+
+  const unsigned int row_length = structure.row_length(row);
+  inverses[row] = new FullMatrix<float> (row_length,
+					 row_length); 
+				   // mapping between:
+				   // 1 column number of all
+				   //   entries in this row, and
+				   // 2 the position within this
+				   //   row (as stored in the
+				   //   SparsityPattern object
+				   //
+				   // since we do not explicitely
+				   // consider nonsysmmetric sparsity
+				   // patterns, the first element
+				   // of each entry simply denotes
+				   // all degrees of freedom that
+				   // couple with #row#.
+  local_index.clear ();
+  for (unsigned int i=0; i<row_length; ++i)
+    local_index.insert(pair<unsigned int, unsigned int>
+		       (structure.column_number(row, i), i));
+  
+				   // Build local matrix and rhs
+  for (map<unsigned int, unsigned int>::const_iterator is=local_index.begin();
+       is!=local_index.end(); ++is)
+    {
+				       // irow loops over all DoFs that
+				       // couple with the present DoF
+      const unsigned int irow = is->first;
+				       // index of DoF irow in the matrix
+				       // row corresponding to DoF #row#.
+				       // runs between 0 and row_length
+      const unsigned int i = is->second;
+				       // number of DoFs coupling to
+				       // irow (including irow itself)
+      const unsigned int irow_length = structure.row_length(irow);
+      
+				       // for all the DoFs that irow
+				       // couples with
+      for (unsigned int j=0; j<irow_length; ++j)
+	{
+					   // col is the number of
+					   // this dof
+	  const unsigned int col = structure.column_number(irow, j);
+					   // find out whether this DoF
+					   // (that couples with #irow#,
+					   // which itself couples with
+					   // #row#) also couples with
+					   // #row#.
+	  const map<unsigned int, unsigned int>::const_iterator js
+	    = local_index.find(col);
+	  
+	  if (js != local_index.end())
+	    (*inverses[row])(i,js->second) = matrix->raw_entry(irow,j);
+	};
+    };
+  
+				   // Compute new values
+  inverses[row]->gauss_jordan();
 };
 
 
 
+
 template<typename number>
 template<typename number2>
 void