NhsSystemWithImplicitSolver.hpp

/*

Copyright (C) University of Oxford, 2005-2009

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.

Chaste is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation, either version 2.1 of the License, or
(at your option) any later version.

Chaste is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details. The offer of Chaste under the terms of the
License is subject to the License being interpreted in accordance with
English Law and subject to any action against the University of Oxford
being under the jurisdiction of the English Courts.

You should have received a copy of the GNU Lesser General Public License
along with Chaste. If not, see <http://www.gnu.org/licenses/>.

*/
#ifndef NHSSYSTEMWITHIMPLICITSOLVER_HPP_
#define NHSSYSTEMWITHIMPLICITSOLVER_HPP_

#include "NhsCellularMechanicsOdeSystem.hpp"


class NhsSystemWithImplicitSolver : public NhsCellularMechanicsOdeSystem
{
private:
    const static double mTolerance = 1e-10;

    double mDt;

    bool mUseImplicitExplicitSolveForZ;

    std::vector<double> mTempStoredStateVariables;
    std::vector<double> mCurrentStateVars;

    double mActiveTensionInitialGuess;
    double mActiveTensionSolution;

    void ImplicitSolveForActiveTension();
    double CalcActiveTensionResidual(double activeTensionGuess);

    double ImplicitSolveForCaTrop(double newActiveTension);

    double ImplicitSolveForZ(double newCaTrop);
    double CalcZResidual(double z, double newCaTrop);
    double ImplicitExplicitSolveForZ(double newCaTrop);

    double ImplicitSolveForQ();

//    /**
//     *  Instead of solving an ODE for Qi, assume that the Qi equations reach a static
//     *  solution on a timescale much smaller than thatt of the deformation, and therefore
//     *  solve the algebraic equation 0 = A_i lambda_dot - alpha_i Q_i to Q_i(t).
//     *
//     *  This method returns Q = Q1+Q2+Q3
//     */
//    double QuasiStaticSolveForQ();

public :
    NhsSystemWithImplicitSolver();

    void SetActiveTensionInitialGuess(double activeTensionInitialGuess);

    void SolveDoNotUpdate(double startTime, double endTime, double timestep);

    void UpdateStateVariables();

    void UseImplicitExplicitSolveForZ(bool useImplicitExplicitSolveForZ = true);

    double GetActiveTensionAtNextTime();
};

#endif /*NHSSYSTEMWITHIMPLICITSOLVER_HPP_*/

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