/**
* Simulates the system over the next interval of time. The timestep
* is given as argument.
*
* @param ds A C_FLOAT64 specifying the timestep
*/
C_FLOAT64 CTauLeapMethod::doSingleStep(C_FLOAT64 ds)
{
C_FLOAT64 Lambda, Tmp, Tau, Tau1, Tau2;
updatePropensities();
mAvgDX = 0.0;
mSigDX = 0.0;
CMathReaction * pReaction = mReactions.array();
const C_FLOAT64 * pAmu = mAmu.array();
const C_FLOAT64 * pAmuEnd = pAmu + mNumReactions;
const C_FLOAT64 * pFirstSpecies = mContainerState.array() + mFirstReactionSpeciesIndex;
for (; pAmu != pAmuEnd; ++pAmu, ++pReaction)
{
const CMathReaction::Balance & Balance = pReaction->getNumberBalance();
const CMathReaction::SpeciesBalance * it = Balance.array();
const CMathReaction::SpeciesBalance * end = it + Balance.size();
for (; it != end; ++it)
{
mAvgDX[it->first - pFirstSpecies] += it->second **pAmu;
mSigDX[it->first - pFirstSpecies] += it->second * it->second **pAmu;
}
}
Tau1 = Tau2 = std::numeric_limits< C_FLOAT64 >::infinity();
const C_FLOAT64 * pSpecies = mContainerState.array() + mFirstReactionSpeciesIndex;
const C_FLOAT64 * pSpeciesEnd = pSpecies + mNumReactionSpecies;
C_FLOAT64 * pAvgDX = mAvgDX.array();
C_FLOAT64 * pSigDX = mSigDX.array();
for (; pSpecies != pSpeciesEnd; ++pSpecies, ++pAvgDX, ++pSigDX)
{
if ((Tmp = mEpsilon * fabs(*pSpecies)) < 1.0)
Tmp = 1.0;
*pAvgDX = Tmp / fabs(*pAvgDX);
*pSigDX = (Tmp * Tmp) / fabs(*pSigDX);
if (Tau1 > *pAvgDX)
Tau1 = *pAvgDX;
if (Tau2 > *pSigDX)
Tau2 = *pSigDX;
}
Tau = std::min(Tau1, Tau2);
if (ds < Tau)
Tau = ds;
pAmu = mAmu.array();
C_FLOAT64 * pK = mK.array();
C_FLOAT64 * pKEnd = pK + mNumReactions;
for (; pAmu != pAmuEnd; ++pAmu, ++pK)
{
Lambda = *pAmu * Tau;
if (Lambda < 0.0)
CCopasiMessage(CCopasiMessage::EXCEPTION, MCTrajectoryMethod + 10);
else if (Lambda > 2.0e9)
CCopasiMessage(CCopasiMessage::EXCEPTION, MCTrajectoryMethod + 26);
*pK = mpRandomGenerator->getRandomPoisson(Lambda);
}
while (!updateSystem())
{
Tau *= 0.5;
pK = mK.array();
for (; pK != pKEnd; ++pK)
{
*pK *= 0.5;
if (*pK < floor(*pK + 0.75))
{
*pK += mpRandomGenerator->getRandomCC() < 0.5 ? - 0.5 : 0.5;
}
}
}
return Tau;
}
/**
* Simulates the system over the next interval of time. The timestep
* is given as argument.
*
* @param ds A C_FLOAT64 specifying the timestep
*/
C_FLOAT64 CTauLeapMethod::doSingleStep(C_FLOAT64 ds)
{
C_FLOAT64 Lambda, Tmp, Tau, Tau1, Tau2;
updatePropensities();
mAvgDX = 0.0;
mSigDX = 0.0;
std::vector< CReactionDependencies >::const_iterator itReaction = mReactionDependencies.begin();
const C_FLOAT64 * pAmu = mAmu.array();
const C_FLOAT64 * pAmuEnd = pAmu + mNumReactions;
for (; pAmu != pAmuEnd; ++pAmu, ++itReaction)
{
const C_FLOAT64 * pMultiplicity = itReaction->mSpeciesMultiplier.array();
const C_FLOAT64 * pMultiplicityEnd = pMultiplicity + itReaction->mSpeciesMultiplier.size();
const size_t * pIndex = itReaction->mMethodSpeciesIndex.array();
for (; pMultiplicity != pMultiplicityEnd; ++pMultiplicity, ++pIndex)
{
mAvgDX[*pIndex] += *pMultiplicity * *pAmu;
mSigDX[*pIndex] += *pMultiplicity * *pMultiplicity * *pAmu;
}
}
Tau1 = Tau2 = std::numeric_limits< C_FLOAT64 >::infinity();
const C_FLOAT64 * pNumber = mMethodState.beginIndependent() + mFirstReactionSpeciesIndex - 1;
const C_FLOAT64 * pNumberEnd = pNumber + mNumReactionSpecies;
C_FLOAT64 * pAvgDX = mAvgDX.array();
C_FLOAT64 * pSigDX = mSigDX.array();
for (; pNumber != pNumberEnd; ++pNumber, ++pAvgDX, ++pSigDX)
{
if ((Tmp = mEpsilon * fabs(*pNumber)) < 1.0)
Tmp = 1.0;
*pAvgDX = Tmp / fabs(*pAvgDX);
*pSigDX = (Tmp * Tmp) / fabs(*pSigDX);
if (Tau1 > *pAvgDX)
Tau1 = *pAvgDX;
if (Tau2 > *pSigDX)
Tau2 = *pSigDX;
}
Tau = std::min(Tau1, Tau2);
if (ds < Tau)
Tau = ds;
pAmu = mAmu.array();
C_FLOAT64 * pK = mK.array();
C_FLOAT64 * pKEnd = pK + mNumReactions;
for (; pAmu != pAmuEnd; ++pAmu, ++pK)
{
Lambda = *pAmu * Tau;
if (Lambda < 0.0)
CCopasiMessage(CCopasiMessage::EXCEPTION, MCTrajectoryMethod + 10);
else if (Lambda > 2.0e9)
CCopasiMessage(CCopasiMessage::EXCEPTION, MCTrajectoryMethod + 26);
*pK = mpRandomGenerator->getRandomPoisson(Lambda);
}
while (!updateSystem())
{
Tau *= 0.5;
pK = mK.array();
for (; pK != pKEnd; ++pK)
{
*pK *= 0.5;
if (*pK < floor(*pK + 0.75))
{
*pK += mpRandomGenerator->getRandomCC() < 0.5 ? - 0.5 : 0.5;
}
}
}
return Tau;
}
