uniform.C

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License
    This file is part of OpenFOAM.
 
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#include "uniform.H"
#include "addToRunTimeSelectionTable.H"
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
namespace distributions
{
    defineTypeNameAndDebug(uniform, 0);
    addToRunTimeSelectionTable(distribution, uniform, dictionary);
}
}
 
 
// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
Foam::scalar Foam::distributions::uniform::Phi(const scalar x) const
{
    if (q() == -1)
    {
        return log(x);
    }
    else
    {
        return integerPow(x, 1 + q())/(1 + q());
    }
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::distributions::uniform::uniform
(
    const dictionary& dict,
    Random& rndGen,
    const label sampleQ
)
:
    FieldDistribution<distribution, uniform>(typeName, dict, rndGen, sampleQ),
    min_(dict.lookupBackwardsCompatible<scalar>({"min", "minValue"})),
    max_(dict.lookupBackwardsCompatible<scalar>({"max", "maxValue"})),
    Phi0_(Phi(min_)),
    Phi1_(Phi(max_))
{
    validateBounds(dict);
    if (q() != 0) validatePositive(dict);
    report();
}
 
 
Foam::distributions::uniform::uniform(const uniform& d, const label sampleQ)
:
    FieldDistribution<distribution, uniform>(d, sampleQ),
    min_(d.min_),
    max_(d.max_),
    Phi0_(Phi(min_)),
    Phi1_(Phi(max_))
{}
 
 
// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
Foam::distributions::uniform::~uniform()
{}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
Foam::scalar Foam::distributions::uniform::sample() const
{
    const scalar s = rndGen_.sample01<scalar>();
 
    if (q() == -1)
    {
        return min_*pow(max_/min_, s);
    }
    else
    {
        const scalar PhiS = (1 - s)*Phi0_ + s*Phi1_;
 
        return integerRoot((1 + q())*PhiS, 1 + q());
    }
}
 
 
Foam::scalar Foam::distributions::uniform::min() const
{
    return min_;
}
 
 
Foam::scalar Foam::distributions::uniform::max() const
{
    return max_;
}
 
 
Foam::scalar Foam::distributions::uniform::mean() const
{
    if (q() == -2)
    {
        return Foam::log(max_/min_)/(Phi1_ - Phi0_);
    }
    else
    {
        const scalar Mu0 = integerPow(min_, 2 + q())/(2 + q());
        const scalar Mu1 = integerPow(max_, 2 + q())/(2 + q());
 
        return (Mu1 - Mu0)/(Phi1_ - Phi0_);
    }
}
 
 
Foam::tmp<Foam::scalarField>
Foam::distributions::uniform::PDF(const scalarField& x) const
{
    if (q() == -1)
    {
        return clipPDF(x, 1/x/Foam::log(max_/min_));
    }
    else
    {
        return clipPDF(x, integerPow(x, q())/(Phi1_ - Phi0_));
    }
}
 
 
// ************************************************************************* //