+ std::vector< std::vector< long double > > masses;
+ masses.resize(0);
+ int count = 0;
+ for (int i = 0; i < index_all.size(); i++) {
+ std::vector< long double > center;
+ center.resize(0, 3);
+ for (int j = 0; j < index_all[i].size(); j++) {
+ center[0] += trajectory[0][count][0];
+ center[1] += trajectory[0][count][1];
+ center[2] += trajectory[0][count][2];
+ count++;
+ }
+ center[0] /= index_all[i].size();
+ center[1] /= index_all[i].size();
+ center[2] /= index_all[i].size();
+ masses.push_back(center);
+ }
+
+