RandomI.H

Go to the documentation of this file.

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2018-2022 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
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
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    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/>.
 
\*---------------------------------------------------------------------------*/
 
#include "Random.H"
 
// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
inline Foam::Random::type Foam::Random::sample()
{
    x_ = (A*x_ + C) % M;
 
    return x_ >> 17;
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
inline Foam::Random::Random(const label s)
:
    x_((type(s) << 16) + 0x330E),
    scalarNormalStored_(false),
    scalarNormalValue_(0)
{}
 
 
// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
inline Foam::Random::~Random()
{}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
inline Foam::scalar Foam::Random::scalar01()
{
    return scalar(sample())/(M >> 17);
}
 
 
inline Foam::scalar Foam::Random::scalarAB(const scalar a, const scalar b)
{
    return a + scalar01()*(b - a);
}
 
 
template<class Type>
inline Type Foam::Random::sample01()
{
    Type value;
 
    for (direction i = 0; i < pTraits<Type>::nComponents; ++ i)
    {
        value.component(i) = scalar01();
    }
 
    return value;
}
 
 
template<>
inline Foam::scalar Foam::Random::sample01()
{
    return scalar01();
}
 
 
template<>
inline Foam::label Foam::Random::sample01()
{
    return sample() % 2;
}
 
 
template<class Type>
inline Type Foam::Random::sampleAB(const Type& a, const Type& b)
{
    return a + cmptMultiply(sample01<Type>(), b - a);
}
 
 
template<>
inline Foam::scalar Foam::Random::sampleAB(const scalar& a, const scalar& b)
{
    return scalarAB(a, b);
}
 
 
template<>
inline Foam::label Foam::Random::sampleAB(const label& a, const label& b)
{
    return a + sample() % (b - a);
}
 
 
template<class Type>
inline Type Foam::Random::sampleNormal()
{
    Type value;
 
    for (direction i = 0; i < pTraits<Type>::nComponents; ++ i)
    {
        value.component(i) = scalarNormal();
    }
 
    return value;
}
 
 
template<>
inline Foam::scalar Foam::Random::sampleNormal()
{
    return scalarNormal();
}
 
 
template<class Container>
inline void Foam::Random::permute(Container& l)
{
    for (label i = 0; i < l.size(); ++ i)
    {
        Swap(l[i], l[sampleAB<label>(i, l.size())]);
    }
}
 
 
// ************************************************************************* //