std::size_t RandomDistribution::sampleIndex()
{
//const double r1 = randomUniform<double>(m_seed);
//const double r2 = randomUniform<double>(m_seed);
//std::size_t k = static_cast<std::size_t>(m_weights.size() * r1);
return sampleIndex(m_seed);
//return r2 < m_probs[k] ? k : m_alias[k];
}
///////////////////////////////////////////////////////////
// given indices for i!=j, sample density j's index
///////////////////////////////////////////////////////////
// uses particles, variance, ind
// uses newPoints, newIndices, trees, Ndens
void gibbs1(unsigned int _Ndens, const BallTreeDensity* _trees,
unsigned long Np, unsigned int Niter,
double *_pts, BallTree::index *_ind,
double *_randU, double* _randN)
{
unsigned int i,j,l;
unsigned long s, maxNp;
Ndens = _Ndens; // SET UP GLOBALS
trees = _trees;
newPoints = _pts; newIndices = _ind;
randU = _randU; randN = _randN;
Ndim = trees[0].Ndim(); // dimension of densities
maxNp = 0; // largest # of particles we deal with
for (unsigned int j=0; j<Ndens; j++) // compute Max Np over all densities
if (maxNp < trees[j].Npts()) maxNp = trees[j].Npts();
ind = new BallTree::index[Ndens]; // ALLOCATE GLOBALS
p = new double[maxNp];
Malmost = new double[Ndim];
Calmost = new double[Ndim];
Nlevels = (unsigned int) (log((double)maxNp)/log((double)2))+1; // how many levels to a balanced binary tree?
particles = new double[Ndim*Ndens];
variance = new double[Ndim*Ndens];
dNpts = new unsigned long[Ndens];
levelList = new BallTree::index*[Ndens];
levelListNew = new BallTree::index*[Ndens];
for (j=0;j<Ndens;j++) {
levelList[j] = new BallTree::index[maxNp];
levelListNew[j] = new BallTree::index[maxNp];
}
for (unsigned long s=0; s<Np; s++) { // (for each sample:)
levelInit();
// for (l=0;l<Nlevels;l++) levelDown();
// for (j=0;j<Ndens;j++) printf("%d ",dNpts[j]);
initIndices(); // sample initial index values
calcIndices();
for (l=0;l<Nlevels;l++) {
samplePoint(newPoints);
levelDown();
sampleIndices(newPoints);
for (i=0;i<Niter;i++) { // perform Gibbs sampling
for (j=0;j<Ndens;j++) {
sampleIndex(j);
}
}
}
for (unsigned int j=0; j<Ndens; j++) // save and
newIndices[j] = trees[j].getIndexOf(ind[j])+1; // return particle label
samplePoint(newPoints); // draw a sample from that label
newIndices += Ndens; // move pointers to next sample
newPoints += Ndim;
}
for (j=0;j<Ndens;j++) { delete[] levelList[j]; delete[] levelListNew[j]; }
delete[] levelList; delete[] levelListNew;
delete[] dNpts;
delete[] ind; delete[] p; delete[] particles; delete[] variance;
delete[] Malmost; delete[] Calmost;
};
double SpecterDistribution::sampleValue(std::uint64_t seed[2]) const
{
return m_energies[sampleIndex(seed)];
}
double SpecterDistribution::sampleValue()
{
return m_energies[sampleIndex()];
}
