cubicEqn.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
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    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::cubicEqn
 
Description
    Cubic equation of the form a*x^3 + b*x^2 + c*x + d = 0
 
SourceFiles
    cubicEqnI.H
    cubicEqn.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef cubicEqn_H
#define cubicEqn_H
 
#include "Roots.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                          Class cubicEqn Declaration
\*---------------------------------------------------------------------------*/
 
class cubicEqn
:
    public VectorSpace<cubicEqn, scalar, 4>
{
public:
 
    //- Coefficient indexing enumeration
    struct coefficient
    {
        enum {a, b, c, d};
    };
 
 
    // Constructors
 
        //- Construct null
        inline cubicEqn();
 
        //- Construct initialised to zero
        inline cubicEqn(const Foam::zero);
 
        //- Construct from components
        inline cubicEqn
        (
            const scalar a,
            const scalar b,
            const scalar c,
            const scalar d
        );
 
 
    // Member Functions
 
        // Access
 
            inline scalar a() const;
            inline scalar b() const;
            inline scalar c() const;
            inline scalar d() const;
 
            inline scalar& a();
            inline scalar& b();
            inline scalar& c();
            inline scalar& d();
 
        //- Evaluate at x
        inline scalar value(const scalar x) const;
 
        //- Evaluate the derivative at x
        inline scalar derivative(const scalar x) const;
 
        //- Estimate the error of evaluation at x
        inline scalar error(const scalar x) const;
 
        //- Get the roots
        Roots<3> roots() const;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#include "cubicEqnI.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //