LinearEquationSystem.h

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// This file is part of the Peano's PETSc extension. For conditions of
// distribution and use, please see the copyright notice at
// www.peano-framework.org
#pragma once
 
#include "tarch/logging/Log.h"
#include "tarch/logging/Statistics.h"
#include "tarch/logging/LogFilter.h"
#include "tarch/logging/LogFilterFileReader.h"
#include "tarch/la/Matrix.h"
 
#include <petscmat.h>
#include <petscsys.h>
#include <petscksp.h>
 
#include <numeric> //for std iota
 
 
namespace petsc {
  class LinearEquationSystem;
}
 
class petsc::LinearEquationSystem{
  public:
    LinearEquationSystem();
    virtual ~LinearEquationSystem();
 
    void printMatrix();
    void printMatrix(std::string filename);
 
    void printRhs();
    void printRhs(std::string filename);
 
    void printX();
    void printX(std::string filename);
 
    int getDoFs() const;
 
    void init( int dofs );
 
    double get(int i) const;
 
    void insert(int row, int col, double val);
 
    void increment(int row, int col, double val);
 
    void insert(int row, double val);
 
    void increment(int row, double val);
 
 
    template <int rows, int columns>
    void insertMatrix(int row, int col, const tarch::la::Matrix<rows,columns,double>& stencil){
      // get a array of row indices we want to insert into, beginning
      // with the argument "row"
      int rowIndices[ stencil.rows() ];
      std::iota(rowIndices, rowIndices + stencil.rows(), row);
 
      // same for columns
      int colIndices[ stencil.cols() ];
      std::iota(colIndices, colIndices + stencil.cols(), col);
 
      // send to petsc
      MatSetValues( _A, stencil.rows(), rowIndices, stencil.cols(), colIndices, stencil.data(), ADD_VALUES );
 
    }
 
    enum class PreconditionerType: int 
    {
      None, LU, JACOBI
    };
 
    enum class KSPSolverType: int
    {
      GMRES, CG
    };
 
    void solve(PreconditionerType pctype = PreconditionerType::None, KSPSolverType ksptype = KSPSolverType::GMRES);
 
    void cleanUpPetscObjects();
 
 
    PCType  getPreconditionerTypeFromEnum(PreconditionerType type);
    KSPType getKSPSolverTypeFromEnum(KSPSolverType type);
 
  private:
    static tarch::logging::Log  _log;
 
    int _dofs;
 
    Mat  _A;
    Vec  _x;
    Vec  _b;
 
};