void QuadTree_delete(QuadTree q){
int i, dim;
if (!q) return;
dim = q->dim;
FREE(q->center);
FREE(q->average);
if (q->data) FREE(q->data);
if (q->qts){
for (i = 0; i < 1<<dim; i++){
QuadTree_delete(q->qts[i]);
}
FREE(q->qts);
}
SingleLinkedList_delete(q->l, node_data_delete);
FREE(q);
}
static mat barnes_hut(mat z)
{
mat lz = mat_new(z->r, z->c);
real* x = (real*) malloc(sizeof(real)*z->r*z->c);
real *center = NULL, *supernode_wgts = NULL, *distances = NULL;
real bh = 0.65, counts = 0; /* Barnes-Hut constant, if width(snode)/dist[i,snode] < bh, treat snode as a supernode.*/
int flag, nsuper, nsupermax, dim = z->c, max_qtree_level = 10; //max_qtree_level, like bh, should also be a command line argument
QuadTree qt = NULL;
int i, j, node;
for(i = 0; i < z->r; i++) {
for(j = 0; j < z->c; j++) {
x[i*z->c + j] = z->m[mindex(i,j,z)];
}
}
qt = QuadTree_new_from_point_list(dim, z->r, max_qtree_level, x, NULL);
for(i = 0; i < z->r; i++) {
QuadTree_get_supernodes(qt, bh, &(x[dim*i]), i, &nsuper, &nsupermax,
¢er, &supernode_wgts, &distances, &counts, &flag);
for(j = 0; j < dim; j++) {
for(node = 0; node < nsuper; node++) {
if(distances[node] > EPSILON) {
lz->m[mindex(i,j,lz)] += supernode_wgts[node]
* (z->m[mindex(i,j,z)]-center[node*dim+j])
/ distances[node];
} else {
lz->m[mindex(i,j,lz)] = 0;
}
}
}
}
free(x);
free(center);
free(supernode_wgts);
free(distances);
QuadTree_delete(qt);
return lz;
}
static mat barnes_hut_cluster(mat z, mat dij, int* clusters, int power)
{
mat lz = mat_new(z->r, z->c);
int k = dij->r;
int n = z->r;
int i, j, qt_i, node;
real** x = (real**) malloc(sizeof(real*)*k);
real** wgts = (real**) malloc(sizeof(real*)*k);
real* x_all = (real*) malloc(sizeof(real)*z->r*z->c);
real *center = NULL, *supernode_wgts = NULL, *distances = NULL;
real bh = 0.65, counts = 0;
int flag, nsuper, nsupermax, dim = z->c, max_qtree_level = 10;
QuadTree* qt = (QuadTree*) malloc(sizeof(QuadTree)*2*k);
int* sizes = (int*) malloc(sizeof(int)*k);
int* curr_loc = (int*) malloc(sizeof(int)*k);
iarrset(sizes,k,0);
iarrset(curr_loc,k,0);
for(i = 0; i < n; i++) {
sizes[clusters[i]]++;
}
for(i = 0; i < k; i++) {
x[i] = (real*) malloc(sizeof(real)*sizes[i]*z->c);
wgts[i] = (real*) malloc(sizeof(real)*sizes[i]);
}
for(i = 0; i < z->r; i++) {
for(j = 0; j < z->c; j++) {
x_all[i*z->c+j] = z->m[mindex(i,j,z)];
}
}
for(i = 0; i < n; i++) {
int cluster = clusters[i];
for(j = 0; j < z->c; j++) {
x[cluster][curr_loc[cluster]*z->c+j] = z->m[mindex(i,j,z)];
}
curr_loc[cluster]++;
}
iarrset(curr_loc,k,0);
for(i = 0; i < n; i++) {
int cluster = clusters[i];
wgts[cluster][curr_loc[cluster]] = dij->m[mindex(cluster,i,dij)] < EPSILON
? 0 : 1.0/pow(dij->m[mindex(cluster,i,dij)],power-1);
curr_loc[cluster]++;
}
for(i = 0; i < k; i++) {
qt[i] = QuadTree_new_from_point_list(dim, sizes[i], max_qtree_level, x[i], NULL);
}
for(i = 0; i < k; i++) {
qt[i+k] = QuadTree_new_from_point_list(dim, sizes[i], max_qtree_level, x[i], wgts[i]);
}
for(i = 0; i < z->r; i++) {
for(qt_i = 0; qt_i < k; qt_i++) {
double d = dij->m[mindex(qt_i,i,dij)];
if(d < EPSILON) { //Node i is the center of some cluster
QuadTree_get_supernodes(qt[qt_i+k], bh, &(x_all[dim*i]), -1, &nsuper, &nsupermax,
¢er, &supernode_wgts, &distances, &counts, &flag);
d = 1;
} else {
QuadTree_get_supernodes(qt[qt_i], bh, &(x_all[dim*i]), -1, &nsuper, &nsupermax,
¢er, &supernode_wgts, &distances, &counts, &flag);
d = 1.0 / pow(d,power-1);
}
for(j = 0; j < dim; j++) {
for(node = 0; node < nsuper; node++) {
if(distances[node] > EPSILON && d > EPSILON)
lz->m[mindex(i,j,lz)] += d*supernode_wgts[node]
* (z->m[mindex(i,j,z)]-center[node*dim+j])
/ distances[node];
}
}
}
}
for(i = 0; i < k; i++) {
free(x[i]);
free(wgts[i]);
}
for(i = 0; i < 2*k; i++) {
QuadTree_delete(qt[i]);
}
free(qt);
free(sizes);
free(curr_loc);
free(x_all);
free(center);
free(distances);
free(supernode_wgts);
return lz;
}
