PetscVecTools.hpp

/*

Copyright (c) 2005-2012, University of Oxford.
All rights reserved.

University of Oxford means the Chancellor, Masters and Scholars of the
University of Oxford, having an administrative office at Wellington
Square, Oxford OX1 2JD, UK.

This file is part of Chaste.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.
 * Neither the name of the University of Oxford nor the names of its
   contributors may be used to endorse or promote products derived from this
   software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#ifndef _PETSCVECTOOLS_HPP_
#define _PETSCVECTOOLS_HPP_

#include "UblasVectorInclude.hpp" // needs to be 'first'

#include <petscvec.h>

class PetscVecTools
{
public:

    static void Finalise(Vec vector);

    static void Display(Vec vector);

    static void Zero(Vec vector);

    static void SetElement(Vec vector, PetscInt row, double value);

    static void AddToElement(Vec vector, PetscInt row, double value);

    static unsigned GetSize(Vec vector);

    static void GetOwnershipRange(Vec vector, PetscInt& lo, PetscInt& hi);

    static double GetElement(Vec vector, PetscInt row);

    static void AddScaledVector(Vec y, Vec x, double scaleFactor);

    static void Scale(Vec vector, double scaleFactor);

    static void WAXPY(Vec w, double a, Vec x, Vec y);

    template<size_t VECTOR_SIZE>
    static void AddMultipleValues(Vec vector, unsigned* vectorIndices, c_vector<double, VECTOR_SIZE>& smallVector)
    {
        PetscInt indices_owned[VECTOR_SIZE];
        PetscInt num_indices_owned = 0;
        PetscInt global_row;
        PetscInt lo, hi;
        GetOwnershipRange(vector, lo, hi);

        for (unsigned row = 0; row<VECTOR_SIZE; row++)
        {
            global_row = vectorIndices[row];
            if (global_row >=lo && global_row <hi)
            {
                indices_owned[num_indices_owned++] = global_row;
            }
        }

        if (num_indices_owned == VECTOR_SIZE)
        {
            VecSetValues(vector,
                         num_indices_owned,
                         indices_owned,
                         smallVector.data(),
                         ADD_VALUES);
        }
        else
        {
            /*
             * We need continuous data, if some of the rows do not belong
             * to the processor their values are not passed to VecSetValues.
             */
            double values[VECTOR_SIZE];
            unsigned num_values_owned = 0;

            for (unsigned row = 0; row<VECTOR_SIZE; row++)
            {
                global_row = vectorIndices[row];
                if (global_row >= lo && global_row < hi)
                {
                    values[num_values_owned++] = smallVector(row);
                }
            }

            VecSetValues(vector,
                         num_indices_owned,
                         indices_owned,
                         values,
                         ADD_VALUES);
        }
    }

    static void SetupInterleavedVectorScatterGather(Vec interleavedVec, VecScatter& rFirstVariableScatterContext, VecScatter& rSecondVariableScatterContext);

    static void DoInterleavedVecScatter(Vec interleavedVec, VecScatter firstVariableScatterContext, Vec firstVariableVec, VecScatter secondVariableScatterContext, Vec secondVariableVec);

    static void DoInterleavedVecGather(Vec interleavedVec, VecScatter firstVariableScatterContext, Vec firstVariableVec, VecScatter secondVariableScatterContext, Vec secondVariableVec);
};

#endif //_PETSCVECTOOLS_HPP_