cubicEqnI.H

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// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

inline Foam::cubicEqn::cubicEqn(const Foam::zero)
:
    VectorSpace<cubicEqn, scalar, 4>(Foam::zero{})
{}


inline Foam::cubicEqn::cubicEqn
(
    const scalar a,
    const scalar b,
    const scalar c,
    const scalar d
)
{
    this->v_[A] = a;
    this->v_[B] = b;
    this->v_[C] = c;
    this->v_[D] = d;
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

inline Foam::scalar Foam::cubicEqn::value(const scalar x) const
{
    return x*(x*(x*a() + b()) + c()) + d();
}


inline Foam::scalar Foam::cubicEqn::derivative(const scalar x) const
{
    return x*(x*3*a() + 2*b()) + c();
}


inline Foam::scalar Foam::cubicEqn::error(const scalar x) const
{
    return
        SMALL*magSqr(x)*(mag(x*a()) + mag(b()))
      + SMALL*mag(x)*(mag(x*(x*a() + b())) + mag(c()))
      + SMALL*(mag(x*(x*(x*a() + b()) + c())) + mag(d()));
}


// ************************************************************************* //