ODESystem.H

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License
    This file is part of OpenFOAM.
 
    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::ODESystem
 
Description
    Abstract base class for the systems of ordinary differential equations.
 
\*---------------------------------------------------------------------------*/
 
#ifndef ODESystem_H
#define ODESystem_H
 
#include "scalarField.H"
#include "scalarMatrices.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                          Class ODESystem Declaration
\*---------------------------------------------------------------------------*/
 
class ODESystem
{
protected:
 
    // Protected Member Functions
 
        //- Print correspondence between derivatives and Jacobian methods
        void check
        (
            const scalar x,
            const scalarField& y,
            const scalarField& dy,
            const label li
        ) const;
 
 
public:
 
    // Constructors
 
        //- Construct null
        ODESystem();
 
 
    //- Destructor
    virtual ~ODESystem();
 
 
    // Member Functions
 
        //- Return the number of equations in the system
        virtual label nEqns() const = 0;
 
        //- Calculate the derivatives in dydx
        //  for the current state x and y
        //  and optional index into the list of systems to solve li
        virtual void derivatives
        (
            const scalar x,
            const scalarField& y,
            const label li,
            scalarField& dydx
        ) const = 0;
 
        //- Calculate the Jacobian of the system
        //  for the current state x and y
        //  and optional index into the list of systems to solve li.
        //  Need by stiff-system solvers
        virtual void jacobian
        (
            const scalar x,
            const scalarField& y,
            const label li,
            scalarField& dfdx,
            scalarSquareMatrix& dfdy
        ) const = 0;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //