From dc248b94989af1ae62e2f68e095563df0ff3d751 Mon Sep 17 00:00:00 2001
From: guido <guido@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Fri, 19 Oct 2001 08:31:30 +0000
Subject: [PATCH] adding functions for PreconditionBlockJacobi

git-svn-id: https://svn.dealii.org/trunk@5156 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/lac/include/lac/precondition_block.h  | 30 ++++++++++++
 .../lac/precondition_block.templates.h        | 49 ++++++++++++++++---
 deal.II/lac/source/precondition_block.cc      | 24 +++++++++
 3 files changed, 97 insertions(+), 6 deletions(-)

diff --git a/deal.II/lac/include/lac/precondition_block.h b/deal.II/lac/include/lac/precondition_block.h
index 9be09e0af7..f2ce8a7b65 100644
--- a/deal.II/lac/include/lac/precondition_block.h
+++ b/deal.II/lac/include/lac/precondition_block.h
@@ -338,6 +338,36 @@ class PreconditionBlockJacobi : public virtual Subscriptor,
 				      */
     template <typename number2>
     void Tvmult (Vector<number2>&, const Vector<number2>&) const;
+				     /**
+				      * Execute block Jacobi
+				      * preconditioning, adding to @p{dst}.
+				      *
+				      * This function will
+				      * automatically use the inverse
+				      * matrices if they exist, if not
+				      * then BlockJacobi will need
+				      * much time inverting the
+				      * diagonal block matrices in
+				      * each preconditioning step.
+				      */
+    template <typename number2>
+    void vmult_add (Vector<number2>&, const Vector<number2>&) const;
+
+				     /**
+				      * Same as @p{vmult_add}, since Jacobi is symmetric.
+				      */
+    template <typename number2>
+    void Tvmult_add (Vector<number2>&, const Vector<number2>&) const;
+
+  private:
+				   /**
+				    * Actual implementation of the
+				    * preconditioner.
+				    */
+    template <typename number2>
+    void do_vmult (Vector<number2>&,
+		   const Vector<number2>&,
+		   bool adding) const;
 };
 
 
diff --git a/deal.II/lac/include/lac/precondition_block.templates.h b/deal.II/lac/include/lac/precondition_block.templates.h
index a676d2f1b5..b7d9b53a74 100644
--- a/deal.II/lac/include/lac/precondition_block.templates.h
+++ b/deal.II/lac/include/lac/precondition_block.templates.h
@@ -226,8 +226,9 @@ PreconditionBlock<number,inverse_type>::memory_consumption () const
 template <typename number, typename inverse_type>
 template <typename number2>
 void PreconditionBlockJacobi<number,inverse_type>
-::vmult (Vector<number2>       &dst,
-	 const Vector<number2> &src) const
+::do_vmult (Vector<number2>       &dst,
+	    const Vector<number2> &src,
+	    bool adding) const
 {
 				   // introduce the following typedef
 				   // since in the use of exceptions,
@@ -278,7 +279,10 @@ void PreconditionBlockJacobi<number,inverse_type>
 	  M_cell.backward(x_cell,b_cell);
 					   // distribute x_cell to dst
 	  for (row=cell*blocksize, row_cell=0; row_cell<blocksize; ++row_cell, ++row)
-	    dst(row)=x_cell(row_cell);
+	    if (adding)
+	      dst(row)+=x_cell(row_cell);
+	    else
+	      dst(row)=x_cell(row_cell);
 	  
 	  begin_diag_block+=blocksize;
 	}
@@ -293,7 +297,10 @@ void PreconditionBlockJacobi<number,inverse_type>
 	inverse(cell).vmult(x_cell, b_cell);
 					 // distribute x_cell to dst
 	for (row=cell*blocksize, row_cell=0; row_cell<blocksize; ++row_cell, ++row)
-	  dst(row)=x_cell(row_cell);
+	  if (adding)
+	    dst(row)+=x_cell(row_cell);
+	  else
+	    dst(row)=x_cell(row_cell);
 	
 	begin_diag_block+=blocksize;
       }
@@ -304,10 +311,40 @@ void PreconditionBlockJacobi<number,inverse_type>
 template <typename number, typename inverse_type>
 template <typename number2>
 void PreconditionBlockJacobi<number,inverse_type>
-::Tvmult (Vector<number2>       &dst,
+::vmult (Vector<number2>       &dst,
 	 const Vector<number2> &src) const
 {
-  vmult(dst, src);
+  do_vmult(dst, src, false);
+}
+
+
+template <typename number, typename inverse_type>
+template <typename number2>
+void PreconditionBlockJacobi<number,inverse_type>
+::Tvmult (Vector<number2>       &dst,
+	  const Vector<number2> &src) const
+{
+  do_vmult(dst, src, false);
+}
+
+
+template <typename number, typename inverse_type>
+template <typename number2>
+void PreconditionBlockJacobi<number,inverse_type>
+::vmult_add (Vector<number2>       &dst,
+	     const Vector<number2> &src) const
+{
+  do_vmult(dst, src, true);
+}
+
+
+template <typename number, typename inverse_type>
+template <typename number2>
+void PreconditionBlockJacobi<number,inverse_type>
+::Tvmult_add (Vector<number2>       &dst,
+	      const Vector<number2> &src) const
+{
+  do_vmult(dst, src, true);
 }
 
 
diff --git a/deal.II/lac/source/precondition_block.cc b/deal.II/lac/source/precondition_block.cc
index 193c67f049..529aa78261 100644
--- a/deal.II/lac/source/precondition_block.cc
+++ b/deal.II/lac/source/precondition_block.cc
@@ -43,6 +43,14 @@ template void PreconditionBlockJacobi<float, float>::Tvmult
 (Vector<float> &, const Vector<float> &) const;
 template void PreconditionBlockJacobi<float, float>::Tvmult
 (Vector<double> &, const Vector<double> &) const;
+template void PreconditionBlockJacobi<float, float>::vmult_add
+(Vector<float> &, const Vector<float> &) const;
+template void PreconditionBlockJacobi<float, float>::vmult_add
+(Vector<double> &, const Vector<double> &) const;
+template void PreconditionBlockJacobi<float, float>::Tvmult_add
+(Vector<float> &, const Vector<float> &) const;
+template void PreconditionBlockJacobi<float, float>::Tvmult_add
+(Vector<double> &, const Vector<double> &) const;
 
 template class PreconditionBlockJacobi<double, float>;
 
@@ -54,6 +62,14 @@ template void PreconditionBlockJacobi<double, float>::Tvmult
 (Vector<float> &, const Vector<float> &) const;
 template void PreconditionBlockJacobi<double, float>::Tvmult
 (Vector<double> &, const Vector<double> &) const;
+template void PreconditionBlockJacobi<double, float>::vmult_add
+(Vector<float> &, const Vector<float> &) const;
+template void PreconditionBlockJacobi<double, float>::vmult_add
+(Vector<double> &, const Vector<double> &) const;
+template void PreconditionBlockJacobi<double, float>::Tvmult_add
+(Vector<float> &, const Vector<float> &) const;
+template void PreconditionBlockJacobi<double, float>::Tvmult_add
+(Vector<double> &, const Vector<double> &) const;
 
 template class PreconditionBlockJacobi<double, double>;
 
@@ -65,6 +81,14 @@ template void PreconditionBlockJacobi<double, double>::Tvmult
 (Vector<float> &, const Vector<float> &) const;
 template void PreconditionBlockJacobi<double, double>::Tvmult
 (Vector<double> &, const Vector<double> &) const;
+template void PreconditionBlockJacobi<double, double>::vmult_add
+(Vector<float> &, const Vector<float> &) const;
+template void PreconditionBlockJacobi<double, double>::vmult_add
+(Vector<double> &, const Vector<double> &) const;
+template void PreconditionBlockJacobi<double, double>::Tvmult_add
+(Vector<float> &, const Vector<float> &) const;
+template void PreconditionBlockJacobi<double, double>::Tvmult_add
+(Vector<double> &, const Vector<double> &) const;
 
 /*--------------------- PreconditionBlockGaussSeidel -----------------------*/
 
-- 
2.39.5