From 49c77c1c08093f6d3d76d3bf4f1f0d9ebf9e8218 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Mon, 5 Nov 2012 00:52:50 +0000
Subject: [PATCH] Partial merge from the parallel_mg branch: Introduce Tvmult
 for Trilinos preconditioners.

git-svn-id: https://svn.dealii.org/trunk@27379 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/doc/news/changes.h                    |  6 ++
 .../deal.II/lac/trilinos_precondition.h       | 82 +++++++++++++++++++
 2 files changed, 88 insertions(+)

diff --git a/deal.II/doc/news/changes.h b/deal.II/doc/news/changes.h
index 0a6fcfc76b..db2c26e5a2 100644
--- a/deal.II/doc/news/changes.h
+++ b/deal.II/doc/news/changes.h
@@ -154,6 +154,12 @@ DoFHandler, in particular removal of specializations.
 <h3>Specific improvements</h3>
 
 <ol>
+<li> New: The TrilinosWrappers::PreconditionBase class now has
+a function TrilinosWrappers::PreconditionBase::Tvmult that
+allows applying the transpose preconditioner.
+<br>
+(Guido Kanschat, 2012/11/04)
+
 <li> New: The parallel::distributed::Triangulation::n_global_levels()
 function returns the maximal refinement level over all involved
 processors.
diff --git a/deal.II/include/deal.II/lac/trilinos_precondition.h b/deal.II/include/deal.II/lac/trilinos_precondition.h
index aed66aaded..025817f8be 100644
--- a/deal.II/include/deal.II/lac/trilinos_precondition.h
+++ b/deal.II/include/deal.II/lac/trilinos_precondition.h
@@ -113,6 +113,12 @@ namespace TrilinosWrappers
                                         * Apply the preconditioner.
                                         */
       void vmult (VectorBase       &dst,
+                  const VectorBase &src) const;
+
+                                       /**
+                                        * Apply transpose the preconditioner.
+                                        */
+      void Tvmult (VectorBase       &dst,
                   const VectorBase &src) const;
 
                                        /**
@@ -123,6 +129,16 @@ namespace TrilinosWrappers
                                         * class.
                                         */
       void vmult (dealii::Vector<double>       &dst,
+                  const dealii::Vector<double> &src) const;
+
+                                       /**
+                                        * Apply the transpose preconditioner on
+                                        * deal.II data structures
+                                        * instead of the ones provided
+                                        * in the Trilinos wrapper
+                                        * class.
+                                        */
+      void Tvmult (dealii::Vector<double>       &dst,
                   const dealii::Vector<double> &src) const;
 
                                        /**
@@ -132,6 +148,15 @@ namespace TrilinosWrappers
                                         * wrapper class.
                                         */
       void vmult (dealii::parallel::distributed::Vector<double>       &dst,
+                  const dealii::parallel::distributed::Vector<double> &src) const;
+
+                                       /**
+                                        * Apply the transpose preconditioner on deal.II
+                                        * parallel data structures instead of
+                                        * the ones provided in the Trilinos
+                                        * wrapper class.
+                                        */
+      void Tvmult (dealii::parallel::distributed::Vector<double>       &dst,
                   const dealii::parallel::distributed::Vector<double> &src) const;
 
                                        /**
@@ -1488,6 +1513,23 @@ namespace TrilinosWrappers
     AssertThrow (ierr == 0, ExcTrilinosError(ierr));
   }
 
+  inline
+  void
+  PreconditionBase::Tvmult (VectorBase       &dst,
+                           const VectorBase &src) const
+  {
+    Assert (dst.vector_partitioner().SameAs(preconditioner->OperatorRangeMap()),
+            ExcNonMatchingMaps("dst"));
+    Assert (src.vector_partitioner().SameAs(preconditioner->OperatorDomainMap()),
+            ExcNonMatchingMaps("src"));
+    
+    preconditioner->SetUseTranspose(true);
+    const int ierr = preconditioner->ApplyInverse (src.trilinos_vector(),
+                                                   dst.trilinos_vector());
+    AssertThrow (ierr == 0, ExcTrilinosError(ierr));
+    preconditioner->SetUseTranspose(false);
+  }
+
 
                                         // For the implementation of
                                         // the <code>vmult</code>
@@ -1531,6 +1573,26 @@ namespace TrilinosWrappers
   }
 
 
+  inline
+  void PreconditionBase::Tvmult (dealii::Vector<double>       &dst,
+                                const dealii::Vector<double> &src) const
+  {
+    AssertDimension (static_cast<int>(dst.size()),
+                     preconditioner->OperatorDomainMap().NumMyElements());
+    AssertDimension (static_cast<int>(src.size()),
+                     preconditioner->OperatorRangeMap().NumMyElements());
+    Epetra_Vector tril_dst (View, preconditioner->OperatorDomainMap(),
+                            dst.begin());
+    Epetra_Vector tril_src (View, preconditioner->OperatorRangeMap(),
+                            const_cast<double*>(src.begin()));
+
+    preconditioner->SetUseTranspose(true);
+    const int ierr = preconditioner->ApplyInverse (tril_src, tril_dst);
+    AssertThrow (ierr == 0, ExcTrilinosError(ierr));
+    preconditioner->SetUseTranspose(false);
+  }
+
+
 
   inline
   void
@@ -1550,6 +1612,26 @@ namespace TrilinosWrappers
     AssertThrow (ierr == 0, ExcTrilinosError(ierr));
   }
 
+  inline
+  void
+  PreconditionBase::Tvmult (parallel::distributed::Vector<double>       &dst,
+                           const parallel::distributed::Vector<double> &src) const
+  {
+    AssertDimension (static_cast<int>(dst.local_size()),
+                     preconditioner->OperatorDomainMap().NumMyElements());
+    AssertDimension (static_cast<int>(src.local_size()),
+                     preconditioner->OperatorRangeMap().NumMyElements());
+    Epetra_Vector tril_dst (View, preconditioner->OperatorDomainMap(),
+                            dst.begin());
+    Epetra_Vector tril_src (View, preconditioner->OperatorRangeMap(),
+                            const_cast<double*>(src.begin()));
+
+    preconditioner->SetUseTranspose(true);
+    const int ierr = preconditioner->ApplyInverse (tril_src, tril_dst);
+    AssertThrow (ierr == 0, ExcTrilinosError(ierr));
+    preconditioner->SetUseTranspose(false);
+  }
+
 #endif
 
 }
-- 
2.39.5