From: Toby D. Young <tyoung@ippt.pan.pl>
Date: Sat, 20 Apr 2013 12:18:30 +0000 (+0000)
Subject: Interface to SLEPc's interface to a LAPACK direct solver.
X-Git-Tag: v8.0.0~650
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c29fa0c1699ffeda1fa9b1b613cdbec8854d95e;p=dealii.git

Interface to SLEPc's interface to a LAPACK direct solver.

git-svn-id: https://svn.dealii.org/trunk@29349 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/include/deal.II/lac/slepc_solver.h b/deal.II/include/deal.II/lac/slepc_solver.h
index 3d1eb2ff10..7985623114 100644
--- a/deal.II/include/deal.II/lac/slepc_solver.h
+++ b/deal.II/include/deal.II/lac/slepc_solver.h
@@ -655,6 +655,50 @@ namespace SLEPcWrappers
     virtual void set_solver_type (EPS &eps) const;
   };
 
+
+  /**
+   * An implementation of the solver interface using the SLEPc LAPACK
+   * direct solver.
+   *
+   * @ingroup SLEPcWrappers
+   *
+   * @author Toby D. Young 2013
+   */
+  class SolverLAPACK : public SolverBase
+  {
+  public:
+
+    /**
+     * Standardized data struct to pipe additional data to the solver,
+     * should it be needed.
+     */
+    struct AdditionalData
+    {};
+
+    /**
+     * SLEPc solvers will want to have an MPI communicator context
+     * over which computations are parallelized. By default, this
+     * carries the same behaviour has the PETScWrappers, but you can
+     * change that.
+     */
+    SolverLAPACK (SolverControl        &cn,
+		  const MPI_Comm       &mpi_communicator = PETSC_COMM_SELF,
+		  const AdditionalData &data = AdditionalData());
+
+  protected:
+
+    /**
+     * Store a copy of the flags for this particular solver.
+     */
+    const AdditionalData additional_data;
+
+    /**
+     * Function that takes a Eigenvalue Problem Solver context object,
+     * and sets the type of solver that is appropriate for this class.
+     */
+    virtual void set_solver_type (EPS &eps) const;
+  };
+
   // --------------------------- inline and template functions -----------
   /**
    * This is declared here to make it possible to take a std::vector
diff --git a/deal.II/source/lac/slepc_solver.cc b/deal.II/source/lac/slepc_solver.cc
index a7bdf48670..c76b6c4331 100644
--- a/deal.II/source/lac/slepc_solver.cc
+++ b/deal.II/source/lac/slepc_solver.cc
@@ -460,6 +460,41 @@ namespace SLEPcWrappers
 #endif
   }
 
+
+  /* ---------------------- LAPACK ------------------------- */
+  SolverLAPACK::SolverLAPACK (SolverControl        &cn,
+			      const MPI_Comm       &mpi_communicator,
+			      const AdditionalData &data)
+    :
+    SolverBase (cn, mpi_communicator),
+    additional_data (data)
+  {}
+
+  void
+  SolverLAPACK::set_solver_type (EPS &eps) const
+  {
+    // 'Tis overwhelmingly likely that PETSc/SLEPc *always* has
+    // BLAS/LAPACK, but let's be defensive.
+#if PETSC_HAVE_BLASLAPACK
+    int ierr;
+    ierr = EPSSetType (eps, const_cast<char *>(EPSLAPACK));
+    AssertThrow (ierr == 0, ExcSLEPcError(ierr));
+
+    // hand over the absolute tolerance and the maximum number of
+    // iteration steps to the SLEPc convergence criterion.
+    ierr = EPSSetTolerances (eps, this->solver_control.tolerance(),
+                             this->solver_control.max_steps());
+    AssertThrow (ierr == 0, ExcSLEPcError(ierr));
+#else
+    // Supress compiler warnings about unused paameters.
+    (void) eps;
+
+    Assert ((false),
+            ExcMessage ("Your PETSc/SLEPc installation was not configured with BLAS/LAPACK "
+                        "but this is needed to use the LAPACK solver."));
+#endif
+  }
+
 }
 
 DEAL_II_NAMESPACE_CLOSE