fscanf (f, "%d", &channels);
_data.resize (channels);
for (int i = 0; i < channels; ++i) {
int points;
fscanf (f, "%d", &points);
fscanf (f, "%d", &channels);
_data.resize (channels);
for (int i = 0; i < channels; ++i) {
int points;
fscanf (f, "%d", &points);