WOSPotential::ValueType
WOSPotential::method5(ParticleSet& P)
{
static const double V0 = 0;
/// intialise the particles in WP;
WP->setP(P);
Domain domain; /// create domain;
double branch = 0.0;
double tau = 0.01;
double v0 = -8.709;
double pe = 0.0;
double dpe = 0.0;
for(int irun = 0; irun < m_runs; irun++)
{
domain.runner = WP->R0; /// initialise runner
domain.in_device = true; /// runner is inside device
device->MaximumSphere(domain); /// calc d_{0}
// domain.WalkOnSphere();
double Gwt = domain.ImportanceWalk();
double vD0 = device->OC_contrib0(domain.radius,domain.runner,WP);
double vbare = device->OC_passage(V0,domain,WP);
WP->calcwt();
double vol = 0.0;
while(domain.in_device)
{
device->MaximumSphere(domain);
vol += device->contribk(domain,WP);
domain.WalkOnSphere();
vbare += device->OC_passage(V0,domain,WP);
}
vol *= WP->qwt; /// the half has been included
// double vrun = vol + vbare + vD0;
double vrun = 0.25*(vol + vbare)/Gwt + vD0;
pe += vrun;
dpe += vrun * vrun;
// cout << vrun << '\t' << v0 << '\t' << branch << endl;
}
pe *= m_norm;
branch *= m_norm;
dpe *= m_norm;
dpe = sqrt(m_norm * fabs ( dpe - pe * pe ));
double var = dpe - pe * pe;
cout << "correlated: " << pe << '\t' << dpe << '\t' << var << '\t'
<< branch << '\t' << branch*exp(-0.5*var*tau*tau) << endl;
exit(-1);
return pe;
}
/// importance sampling
WOSPotential::ValueType
WOSPotential::method3(ParticleSet& P)
{
WP->setP(P);
Domain domain;
double pe = 0.0;
double dpe = 0.0;
for(int irun = 0; irun < m_runs; irun++)
{
double vrun = 0.0;
for(int i = 0; i < WP->m_qpts; i++)
/// start run
{
domain.runner = WP->R[i];
domain.in_device = true;
device->MaximumSphere(domain);
double vi = device->contrib0(i,domain,WP);
double Gwt = domain.ImportanceWalk();
double vbare = device->passage(domain);
double vol = 0.0;
while(domain.in_device)
{
device->MaximumSphere(domain);
vol += device->contribk(domain,WP);
domain.WalkOnSphere();
vbare += device->passage(domain);
} /// end walk: runner on boundary
// vi = 0.0; vol = 0.0;
vi = WP->Q[i] * (0.25*( 0.5 * vol + vbare )/Gwt + 0.5*vi);
vrun += vi;
} /// end run/particle loop
pe += vrun;
dpe += vrun * vrun; /// collect statistics
} /// end runners-loop
/// compute estimates
pe *= m_norm;
dpe *= m_norm;
dpe = sqrt(m_norm * fabs ( dpe - pe * pe ));
double var = dpe - pe * pe;
cout << "importance: " << pe << '\t' << dpe << '\t' << var << endl;
exit(-1);
return pe;
}
