randomGeneratorI.H

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License
    This file is part of OpenFOAM.
 
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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
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#include "randomGenerator.H"
#include "Hash.H"
 
// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
inline uint64_t Foam::randomGenerator::seed::x(const bool global) const
{
    const uint64_t localS =
        global ? s_ : s_ + (UINT64_MAX/Pstream::nProcs())*Pstream::myProcNo();
 
    return (localS << 16) + 0x330E;
}
 
 
inline void Foam::randomGenerator::checkSync() const
{
    if (global_)
    {
        uint64_t xMaster = x_;
        Pstream::scatter(xMaster);
        if (xMaster != x_)
        {
            FatalErrorInFunction
                << "Global random number generator is not synchronised"
                << exit(FatalError);
        }
    }
}
 
 
inline uint64_t Foam::randomGenerator::sample()
{
    x_ = (A*x_ + C) % M;
    return x_ >> 17;
}
 
 
inline Foam::scalar Foam::randomGenerator::scalar01NoCheckSync()
{
    return scalar(sample())/(M >> 17);
}
 
 
inline Foam::scalar Foam::randomGenerator::scalarABNoCheckSync
(
    const scalar a,
    const scalar b
)
{
    return a + scalar01NoCheckSync()*(b - a);
}
 
 
template<class Type>
inline Type Foam::randomGenerator::sample01NoCheckSync()
{
    Type value;
    for (direction i = 0; i < pTraits<Type>::nComponents; ++ i)
    {
        value.component(i) = scalar01NoCheckSync();
    }
    return value;
}
 
 
template<>
inline Foam::scalar Foam::randomGenerator::sample01NoCheckSync()
{
    return scalar01NoCheckSync();
}
 
 
template<>
inline Foam::label Foam::randomGenerator::sample01NoCheckSync()
{
    return sample() % 2;
}
 
 
template<class Type>
inline Type Foam::randomGenerator::sampleABNoCheckSync
(
    const Type& a,
    const Type& b
)
{
    return a + cmptMultiply(sample01NoCheckSync<Type>(), b - a);
}
 
 
template<>
inline Foam::scalar Foam::randomGenerator::sampleABNoCheckSync
(
    const scalar& a,
    const scalar& b
)
{
    return scalarABNoCheckSync(a, b);
}
 
 
template<>
inline Foam::label Foam::randomGenerator::sampleABNoCheckSync
(
    const label& a,
    const label& b
)
{
    return a + sample() % (b - a);
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
inline Foam::randomGenerator::seed::seed(const label s)
:
    s_(s)
{}
 
 
inline Foam::randomGenerator::seed::seed(const word& s)
:
    s_(Hash<word>()(s))
{}
 
 
inline Foam::randomGenerator::randomGenerator(const seed s, const bool global)
:
    global_(global),
    x_(s.x(global))
{
    checkSync();
}
 
 
inline Foam::randomGenerator::randomGenerator(const randomGenerator& rndGen)
:
    global_(rndGen.global_),
    x_(rndGen.x_)
{
    checkSync();
}
 
 
inline Foam::randomGenerator::randomGenerator(randomGenerator&& rndGen)
:
    randomGenerator(static_cast<const randomGenerator&>(rndGen))
{}
 
 
// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
inline Foam::randomGenerator::~randomGenerator()
{}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
inline Foam::scalar Foam::randomGenerator::scalar01()
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    return scalar01NoCheckSync();
}
 
 
inline Foam::tmp<Foam::scalarField> Foam::randomGenerator::scalar01
(
    const label n
)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    tmp<scalarField> tValues(new scalarField(n));
    for (label i = 0; i < n; ++ i)
    {
        tValues.ref()[i] = scalar01NoCheckSync();
    }
    return tValues;
}
 
 
inline Foam::scalar Foam::randomGenerator::scalarAB
(
    const scalar a,
    const scalar b
)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    return scalarABNoCheckSync(a, b);
}
 
 
inline Foam::tmp<Foam::scalarField> Foam::randomGenerator::scalarAB
(
    const label n,
    const scalar a,
    const scalar b
)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    tmp<scalarField> tValues(new scalarField(n));
    for (label i = 0; i < n; ++ i)
    {
        tValues.ref()[i] = scalarABNoCheckSync(a, b);
    }
    return tValues;
}
 
 
template<class Type>
inline Type Foam::randomGenerator::sample01()
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    return sample01NoCheckSync<Type>();
}
 
 
template<class Type>
inline Foam::tmp<Foam::Field<Type>> Foam::randomGenerator::sample01
(
    const label n
)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    tmp<Field<Type>> tValues(new Field<Type>(n));
    for (label i = 0; i < n; ++ i)
    {
        tValues.ref()[i] = sample01NoCheckSync<Type>();
    }
    return tValues;
}
 
 
template<class Type>
inline Type Foam::randomGenerator::sampleAB(const Type& a, const Type& b)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    return sampleABNoCheckSync(a, b);
}
 
 
template<class Type>
inline Foam::tmp<Foam::Field<Type>> Foam::randomGenerator::sampleAB
(
    const label n,
    const Type& a,
    const Type& b
)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    tmp<Field<Type>> tValues(new Field<Type>(n));
    for (label i = 0; i < n; ++ i)
    {
        tValues.ref()[i] = sampleABNoCheckSync(a, b);
    }
    return tValues;
}
 
 
template<class Container>
inline void Foam::randomGenerator::permute(Container& l)
{
    #ifdef FULLDEBUG
    checkSync();
    #endif
 
    for (label i = 0; i < l.size(); ++ i)
    {
        Swap(l[i], l[sampleABNoCheckSync<label>(i, l.size())]);
    }
}
 
 
inline Foam::randomGenerator Foam::randomGenerator::generator()
{
    return randomGenerator(sample(), global_);
}
 
 
// ************************************************************************* //