From 99a18b2aad1ad0a90f903d2a82fb5ba9f885436a Mon Sep 17 00:00:00 2001
From: steigemann <steigemann@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Fri, 26 Oct 2012 16:10:53 +0000
Subject: [PATCH] Interface to PETSc::PreconditionNone and ParaSails
 Preconditioner from the Hypre Suite

git-svn-id: https://svn.dealii.org/trunk@27207 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/source/lac/petsc_precondition.cc | 144 +++++++++++++++++++++++
 1 file changed, 144 insertions(+)

diff --git a/deal.II/source/lac/petsc_precondition.cc b/deal.II/source/lac/petsc_precondition.cc
index 2df82399d2..c6b468c013 100644
--- a/deal.II/source/lac/petsc_precondition.cc
+++ b/deal.II/source/lac/petsc_precondition.cc
@@ -483,6 +483,150 @@ namespace PETScWrappers
   }
 
 
+/* ----------------- PreconditionParaSails -------------------- */
+
+  PreconditionParaSails::AdditionalData::
+  AdditionalData(const unsigned int symmetric,
+                 const unsigned int n_levels,
+                 const double threshold,
+                 const double filter,
+                 const bool output_details)
+                  :
+                  symmetric(symmetric),
+                  n_levels(n_levels),
+                  threshold(threshold),
+                  filter(filter),
+                  output_details(output_details)
+  {}
+
+
+  PreconditionParaSails::PreconditionParaSails ()
+  {}
+
+
+  PreconditionParaSails::PreconditionParaSails (const MatrixBase     &matrix,
+                                                const AdditionalData &additional_data)
+  {
+    initialize(matrix, additional_data);
+  }
+
+
+  void
+  PreconditionParaSails::initialize (const MatrixBase     &matrix_,
+                                     const AdditionalData &additional_data_)
+  {
+    matrix = static_cast<Mat>(matrix_);
+    additional_data = additional_data_;
+
+#ifdef PETSC_HAVE_HYPRE
+    create_pc();
+
+    int ierr;
+    ierr = PCSetType (pc, const_cast<char *>(PCHYPRE));
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+
+    ierr = PCHYPRESetType(pc, "parasails");
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+
+    if (additional_data.output_details)
+      PetscOptionsSetValue("-pc_hypre_parasails_logging","1");
+
+    Assert ((additional_data.symmetric == 0 ||
+             additional_data.symmetric == 1 ||
+             additional_data.symmetric == 2),
+            ExcMessage("ParaSails parameter symmetric can only be equal to 0, 1, 2!"));
+
+    std::stringstream ssStream;
+
+    switch (additional_data.symmetric)
+      {
+        case 0:
+        {
+          ssStream << "nonsymmetric";
+          break;
+        }
+
+        case 1:
+        {
+          ssStream << "SPD";
+          break;
+        }
+
+        case 2:
+        {
+          ssStream << "nonsymmetric,SPD";
+          break;
+        }
+
+        default:
+          Assert (false,
+                  ExcMessage("ParaSails parameter symmetric can only be equal to 0, 1, 2!"));
+      };
+
+    PetscOptionsSetValue("-pc_hypre_parasails_sym",ssStream.str().c_str());
+
+    PetscOptionsSetValue("-pc_hypre_parasails_nlevels",
+                         Utilities::int_to_string(
+                           additional_data.n_levels
+                         ).c_str());
+
+    ssStream.str(""); // empty the stringstream
+    ssStream << additional_data.threshold;
+    PetscOptionsSetValue("-pc_hypre_parasails_thresh", ssStream.str().c_str());
+
+    ssStream.str(""); // empty the stringstream
+    ssStream << additional_data.filter;
+    PetscOptionsSetValue("-pc_hypre_parasails_filter", ssStream.str().c_str());
+
+    ierr = PCSetFromOptions (pc);
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+
+    ierr = PCSetUp (pc);
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+
+#else // PETSC_HAVE_HYPRE
+    (void)pc;
+    Assert (false,
+            ExcMessage ("Your PETSc installation does not include a copy of "
+                        "the hypre package necessary for this preconditioner."));
+#endif
+  }
+
+
+/* ----------------- PreconditionNone ------------------------- */
+
+  PreconditionNone::PreconditionNone ()
+  {}
+
+
+  PreconditionNone::PreconditionNone (const MatrixBase     &matrix,
+                                      const AdditionalData &additional_data)
+  {
+    initialize (matrix, additional_data);
+  }
+
+
+  void
+  PreconditionNone::initialize (const MatrixBase     &matrix_,
+                                const AdditionalData &additional_data_)
+  {
+    matrix = static_cast<Mat>(matrix_);
+    additional_data = additional_data_;
+
+    create_pc();
+
+    int ierr;
+    ierr = PCSetType (pc, const_cast<char *>(PCNONE));
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+
+    ierr = PCSetFromOptions (pc);
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+
+    ierr = PCSetUp (pc);
+    AssertThrow (ierr == 0, ExcPETScError(ierr));
+  }
+
+
 /* ----------------- PreconditionLU -------------------- */
 
   PreconditionLU::AdditionalData::
-- 
2.39.5