///////////////////////////////////////////////////////////
// given a point X, sample indices of all input densities
///////////////////////////////////////////////////////////
// uses Npts, trees, ind, particles, variance, Cwtg
void sampleIndices(double* X) {
unsigned int i,j,k;
unsigned long z;
BallTree::index zz;
for (j=0;j<Ndens;j++) {
unsigned long dNp = dNpts[j]; //trees[j].Npts();
double pT = 0;
for (z=0, zz=levelList[j][0]; z<dNp; zz=levelList[j][++z]) {
p[z] = 0;
for (i=0; i<Ndim; i++) {
double tmp = X[i] - trees[j].mean(zz)[i];
p[z] += (tmp*tmp)/ trees[j].bw(zz)[i];
p[z] += log(trees[j].bw(zz)[i]);
}
p[z] = exp( -0.5 * p[z] ) * trees[j].weight(zz);
pT += p[z];
}
for (z=0; z<dNp; z++) p[z] /= pT;
for (z=1; z<dNp; z++) p[z] += p[z-1]; // construct CDF and sample a
for (z=0, zz=levelList[j][0]; z<dNp-1; zz=levelList[j][++z])
if (*randU <= p[z]) break; // new kernel from jth density
ind[j] = zz; // using those weights
randU++;
}
calcIndices(); // recompute particles, variance
}
///////////////////////////////////////////////////////////
// uses particles, variance, ind
// uses newPoints, newIndices, trees, Ndens
void gibbs2(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];
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 (s=0; s<Np; s++) {
levelInit();
initIndices();
calcIndices();
///////////////////////////////////////////////////////////////
// Perform Gibbs sampling only if multiple densities in product
///////////////////////////////////////////////////////////////
samplePoint(newPoints);
for (l=0;l<Nlevels;l++) {
levelDown();
for (i=0;i<Niter;i++) {
sampleIndices(newPoints);
samplePoint(newPoints);
}}
for (unsigned int j=0; j<Ndens; j++) // save and
newIndices[j] = trees[j].getIndexOf(ind[j])+1; // return particle 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;
};
void MesherFixedEvenStem::getIndices(otTriangles& triangles, unsigned int offset)
{
vertexOffset += offset;
calcIndices(&triangles);
}