RungeKutta2Solver.h

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00001 /******************************************************************************
00002 *       SOFA, Simulation Open-Framework Architecture, version 1.0 beta 3      *
00003 *                (c) 2006-2008 MGH, INRIA, USTL, UJF, CNRS                    *
00004 *                                                                             *
00005 * This library is free software; you can redistribute it and/or modify it     *
00006 * under the terms of the GNU Lesser General Public License as published by    *
00007 * the Free Software Foundation; either version 2.1 of the License, or (at     *
00008 * your option) any later version.                                             *
00009 *                                                                             *
00010 * This library is distributed in the hope that it will be useful, but WITHOUT *
00011 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       *
00012 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License *
00013 * for more details.                                                           *
00014 *                                                                             *
00015 * You should have received a copy of the GNU Lesser General Public License    *
00016 * along with this library; if not, write to the Free Software Foundation,     *
00017 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.          *
00018 *******************************************************************************
00019 *                               SOFA :: Modules                               *
00020 *                                                                             *
00021 * Authors: The SOFA Team and external contributors (see Authors.txt)          *
00022 *                                                                             *
00023 * Contact information: contact@sofa-framework.org                             *
00024 ******************************************************************************/
00025 #ifndef SOFA_COMPONENT_ODESOLVER_RUNGEKUTTA2SOLVER_H
00026 #define SOFA_COMPONENT_ODESOLVER_RUNGEKUTTA2SOLVER_H
00027 
00028 #include <sofa/core/componentmodel/behavior/OdeSolver.h>
00029 #include <sofa/simulation/common/OdeSolverImpl.h>
00030 
00031 namespace sofa
00032 {
00033 
00034 namespace component
00035 {
00036 
00037 namespace odesolver
00038 {
00039 
00041 class RungeKutta2Solver : public sofa::simulation::OdeSolverImpl
00042 {
00043 public:
00044     void solve (double dt);
00045 
00048     virtual double getIntegrationFactor(int inputDerivative, int outputDerivative) const
00049     {
00050         const double dt = getContext()->getDt();
00051         double matrix[3][3] = {
00052             { 1, dt/2, 0},
00053             { 0, 1, dt/2},
00054             { 0, 0, 0}};
00055         if (inputDerivative >= 3 || outputDerivative >= 3)
00056             return 0;
00057         else
00058             return matrix[outputDerivative][inputDerivative];
00059     }
00060 
00064     virtual double getSolutionIntegrationFactor(int outputDerivative) const
00065     {
00066         const double dt = getContext()->getDt();
00067         double vect[3] = { 0.0, dt/2, 1};
00068         if (outputDerivative >= 3)
00069             return 0;
00070         else
00071             return vect[outputDerivative];
00072     }
00073 };
00074 
00075 } // namespace odesolver
00076 
00077 } // namespace component
00078 
00079 } // namespace sofa
00080 
00081 #endif