Browse Source

move meanshift function to meanshift.cu

master
anapt 7 years ago
parent
commit
6d4f864267
  1. 89
      meanshift_declarations.c

89
meanshift_declarations.c

@ -24,95 +24,6 @@ void get_args(int argc, char **argv, int *h){
LABELS_FILENAME = argv[5]; LABELS_FILENAME = argv[5];
} }
int meanshift(double **original_points, double ***shifted_points, int h
, parameters *opt, int iteration){
// allocates space and copies original points on first iteration
if (iteration == 1){
(*shifted_points) = alloc_2d_double(NUMBER_OF_POINTS, DIMENSIONS);
duplicate(original_points, NUMBER_OF_POINTS, DIMENSIONS, shifted_points);
}
// mean shift vector
double **mean_shift_vector;
mean_shift_vector = alloc_2d_double(NUMBER_OF_POINTS, DIMENSIONS);
// initialize elements of mean_shift_vector to inf
for (int i=0;i<NUMBER_OF_POINTS;i++){
for (int j=0;j<DIMENSIONS;j++){
mean_shift_vector[i][j] = DBL_MAX;
}
}
double **kernel_matrix = alloc_2d_double(NUMBER_OF_POINTS, NUMBER_OF_POINTS);
double *denominator = malloc(NUMBER_OF_POINTS * sizeof(double));
// create new y vector
double **new_shift = alloc_2d_double(NUMBER_OF_POINTS, DIMENSIONS);
// find pairwise distance matrix (inside radius)
// [I, D] = rangesearch(x,y,h);
for (int i=0; i<NUMBER_OF_POINTS; i++){
double sum = 0;
for (int j=0; j<NUMBER_OF_POINTS; j++){
double dist_sum = 0;
for (int p=0; p<DIMENSIONS; p++){
double dif = ((*shifted_points)[i])[p]-(original_points[j])[p];
dist_sum += dif * dif;
}
double dist = sqrt(dist_sum);
if (dist < h*h){
kernel_matrix[i][j] = dist * dist;
// compute kernel matrix
double pow = ((-1)*(kernel_matrix[i][j]))/(2*(h*h));
kernel_matrix[i][j] = exp(pow);
} else {
kernel_matrix[i][j] = 0;
}
if (i==j){
kernel_matrix[i][j] += 1;
}
sum = sum + kernel_matrix[i][j];
}
denominator[i] = sum;
// build nominator
for (int j=0; j<DIMENSIONS; j++){
new_shift[i][j] = 0;
for (int k=0; k<NUMBER_OF_POINTS; k++){
new_shift[i][j] += kernel_matrix[i][k] * original_points[k][j];
}
// divide element-wise
new_shift[i][j] = new_shift[i][j] / denominator[i];
// calculate mean-shift vector at the same time
mean_shift_vector[i][j] = new_shift[i][j] - (*shifted_points)[i][j];
}
}
// frees previously shifted points, they're now garbage
free((*shifted_points)[0]);
// updates shifted points pointer to the new array address
shifted_points = &new_shift;
save_matrix((*shifted_points), iteration);
double current_norm = norm(mean_shift_vector, NUMBER_OF_POINTS, DIMENSIONS);
printf("Iteration n. %d, error %f \n", iteration, current_norm);
// clean up this iteration's allocates
free(mean_shift_vector[0]);
free(mean_shift_vector);
free(kernel_matrix[0]);
free(kernel_matrix);
free(denominator);
/** iterate until convergence **/
if (current_norm > opt->epsilon) {
return meanshift(original_points, shifted_points, h, opt, ++iteration);
}
return iteration;
}
// TODO check why there's is a difference in the norm calculate in matlab // TODO check why there's is a difference in the norm calculate in matlab
double norm(double **matrix, int rows, int cols){ double norm(double **matrix, int rows, int cols){

Loading…
Cancel
Save