NekLinSysIterFixedpointJacobi.cpp

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///////////////////////////////////////////////////////////////////////////////
//
// File: NekLinSysIterFixedpointJacobi.cpp
//
// For more information, please see: http://www.nektar.info
//
// The MIT License
//
// Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
// Department of Aeronautics, Imperial College London (UK), and Scientific
// Computing and Imaging Institute, University of Utah (USA).
//
// License for the specific language governing rights and limitations under
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
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// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
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// The above copyright notice and this permission notice shall be included
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//
// Description: NekLinSysIterFixedpointJacobi definition
//
///////////////////////////////////////////////////////////////////////////////
 
#include <LibUtilities/LinearAlgebra/NekLinSysIterFixedpointJacobi.h>
 
using namespace std;
 
namespace Nektar::LibUtilities
{
/**
 * @class  NekLinSysIterFixedpointJacobi
 *
 * Solves a linear system using iterative methods.
 */
string NekLinSysIterFixedpointJacobi::className =
    LibUtilities::GetNekLinSysIterFactory().RegisterCreatorFunction(
        "FixedpointJacobi", NekLinSysIterFixedpointJacobi::create,
        "NekLinSysIterFixedpointJacobi solver.");
 
NekLinSysIterFixedpointJacobi::NekLinSysIterFixedpointJacobi(
    const LibUtilities::SessionReaderSharedPtr &pSession,
    const LibUtilities::CommSharedPtr &vRowComm, const int nDimen,
    const NekSysKey &pKey)
    : NekLinSysIter(pSession, vRowComm, nDimen, pKey)
{
}
 
/**
 *
 */
void NekLinSysIterFixedpointJacobi::v_InitObject()
{
    NekLinSysIter::v_InitObject();
}
 
/**
 *
 */
int NekLinSysIterFixedpointJacobi::v_SolveSystem(
    const int nGlobal, const Array<OneD, const NekDouble> &pRhs,
    Array<OneD, NekDouble> &pSolution, [[maybe_unused]] const int nDir,
    const NekDouble tol, [[maybe_unused]] const NekDouble factor)
{
 
    int niterations = 0;
    m_tolerance     = max(tol, 1.0E-16);
 
    Array<OneD, NekDouble> pSol0(nGlobal);
    Vmath::Vcopy(nGlobal, pSolution, 1, pSol0, 1);
    for (int i = 0; i < m_maxiter; ++i)
    {
        m_operator.DoNekSysFixPointIte(pRhs, pSol0, pSolution);
        Vmath::Vsub(nGlobal, pSolution, 1, pSol0, 1, pSol0, 1);
        m_converged = ConvergenceCheck(i, pSol0, m_tolerance);
        Vmath::Vcopy(nGlobal, pSolution, 1, pSol0, 1);
        niterations++;
        if (m_converged)
        {
            break;
        }
    }
 
    return niterations;
}
} // namespace Nektar::LibUtilities