From 989dcd93ed2fb2bcc44a1f829a4b31e185b293d8 Mon Sep 17 00:00:00 2001
From: wolf <wolf@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Thu, 1 Apr 2004 17:00:41 +0000
Subject: [PATCH] Implement block jacobi, simple version.

git-svn-id: https://svn.dealii.org/trunk@8947 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/lac/include/lac/petsc_precondition.h | 45 ++++++++++++++++++++
 deal.II/lac/source/petsc_precondition.cc     | 23 ++++++++++
 2 files changed, 68 insertions(+)

diff --git a/deal.II/lac/include/lac/petsc_precondition.h b/deal.II/lac/include/lac/petsc_precondition.h
index 939ae226a2..b39f97448c 100644
--- a/deal.II/lac/include/lac/petsc_precondition.h
+++ b/deal.II/lac/include/lac/petsc_precondition.h
@@ -143,6 +143,51 @@ namespace PETScWrappers
 
       
 
+/**
+ * A class that implements the interface to use the PETSc Block Jacobi
+ * preconditioner.
+ *
+ * @author Wolfgang Bangerth, 2004
+ */
+  class PreconditionBlockJacobi : public PreconditionerBase
+  {
+    public:
+                                       /**
+                                        * Standardized data struct to
+                                        * pipe additional flags to the
+                                        * preconditioner.
+                                        */      
+      struct AdditionalData
+      {};
+
+                                       /**
+                                        * Constructor. Take the matrix which
+                                        * is used to form the preconditioner,
+                                        * and additional flags if there are
+                                        * any.
+                                        */
+      PreconditionBlockJacobi (const MatrixBase     &matrix,
+                               const AdditionalData &additional_data = AdditionalData());
+      
+    protected:
+                                       /**
+                                        * Store a copy of the flags for this
+                                        * particular preconditioner.
+                                        */
+      const AdditionalData additional_data;
+
+                                       /**
+                                        * Function that takes a Krylov
+                                        * Subspace Preconditioner context
+                                        * object, and sets the type of
+                                        * preconditioner that is appropriate
+                                        * for the present class.
+                                        */
+      virtual void set_preconditioner_type (PC &pc) const;      
+  };
+
+      
+
 /**
  * A class that implements the interface to use the PETSc SOR
  * preconditioner.
diff --git a/deal.II/lac/source/petsc_precondition.cc b/deal.II/lac/source/petsc_precondition.cc
index 90fe59203e..a060c7e20b 100644
--- a/deal.II/lac/source/petsc_precondition.cc
+++ b/deal.II/lac/source/petsc_precondition.cc
@@ -63,6 +63,29 @@ namespace PETScWrappers
   }
   
 
+/* ----------------- PreconditionJacobi -------------------- */
+
+
+  PreconditionBlockJacobi::
+  PreconditionBlockJacobi (const MatrixBase     &matrix,
+                           const AdditionalData &additional_data)
+                  :
+                  PreconditionerBase (matrix),
+                  additional_data (additional_data)
+  {}
+
+  
+  void
+  PreconditionBlockJacobi::set_preconditioner_type (PC &pc) const
+  {
+                                     // set the right type for the
+                                     // preconditioner
+    int ierr;
+    ierr = PCSetType (pc, const_cast<char *>(PCBJACOBI));
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+  }
+  
+
 /* ----------------- PreconditionSOR -------------------- */
 
   PreconditionSOR::AdditionalData::
-- 
2.39.5