void kd_tree::build_tree(array_2d<double> &mm,
array_1d<double> &nmin, array_1d<double> &nmax){
if(nmin.get_dim()!=mm.get_cols()){
printf("WARNING nimin dim %d cols %d\n",nmin.get_dim(),mm.get_cols());
throw -1;
}
if(nmax.get_dim()!=mm.get_cols()){
printf("WARNING nmax dim %d cols %d\n",nmax.get_dim(),mm.get_cols());
throw -1;
}
search_time=0.0;
search_ct=0;
search_ct_solo=0;
search_time_solo=0.0;
data.reset();
tree.reset();
array_1d<int> inn,use_left,use_right;
array_1d<double> tosort,sorted;
int i,j,k,l,inp;
tol=1.0e-7;
diagnostic=1;
tree.set_dim(mm.get_rows(),4);
data.set_dim(mm.get_rows(),mm.get_cols());
use_left.set_name("kd_tree_constructor_use_left");
use_right.set_name("kd_tree_constructor_use_right");
tree.set_name("kd_tree_tree");
data.set_name("kd_tree_data");
//tree[i][0] will be the dimension being split
//tree[i][1] will be left hand node (so, lt)
//tree[i][2] will be right hand node (so, ge)
//tree[i][3] will be parent
mins.set_name("kd_tree_mins");
maxs.set_name("kd_tree_maxs");
for(i=0;i<data.get_cols();i++){
mins.set(i,nmin.get_data(i));
maxs.set(i,nmax.get_data(i));
}
array_1d<double> vector;
for(i=0;i<data.get_rows();i++){
data.set_row(i,(*mm(i)));
}
sorted.set_name("kd_tree_constructor_sorted");
tosort.set_name("kd_tree_constructor_tosort");
inn.set_name("kd_tree_constructor_inn");
/*sort the data points by their 0th dimension component*/
for(i=0;i<data.get_rows();i++){
tosort.set(i,data.get_data(i,0));
inn.set(i,i);
}
sort_and_check(tosort,sorted,inn);
/*try to pick the median value as the first node in the tree (the
masterparent)*/
inp=data.get_rows()/2;
while(inp>0 && sorted.get_data(inp)-sorted.get_data(inp-1)<tol){
/*make sure that the division doesn't come in the middle of a bunch
of identical points*/
inp--;
}
masterparent=inn.get_data(inp);
/*assign the remaining points to either the left branch or the right
branch of the masterparent*/
for(j=0;j<data.get_rows();j++){
if(masterparent!=j){
if(data.get_data(j,0)<sorted.get_data(inp)){
use_left.add(j);
}
else{
use_right.add(j);
}
}
}
/*organize all of the points on the left branch of the masterparent*/
if(use_left.get_dim()>0){
organize(use_left,0,masterparent,1,use_left.get_dim(),1);
}
else tree.set(masterparent,1,-1);
/*organize all of the points on the right branch of the masterparent*/
if(use_right.get_dim()>0){
organize(use_right,0,masterparent,1,use_right.get_dim(),2);
}
else tree.set(masterparent,2,-1);
tree.set(masterparent,3,-1);/*masterparent has no parent of its own*/
tree.set(masterparent,0,0);/*masterparent split on the 0th dimension*/
/*check to make sure everything has the dimensions that it should*/
if(mins.get_dim()!=maxs.get_dim() || mins.get_dim()!=data.get_cols() || tree.get_rows()!=data.get_rows()){
printf("WARNING tried to make tree but\n");
printf("nmax %d\n",maxs.get_dim());
printf("nmin %d\n",mins.get_dim());
printf("tree %d %d data %d %d\n",tree.get_rows(),tree.get_cols(),
data.get_rows(),data.get_cols());
exit(1);
}
}
