test mergemulti traj at one place

apps/function/multi_traj_functions.cpp

@@ -220,7 +220,7 @@ void filterByPosition(
                     }
                 }
             }
-            pair<size_t, size_t> longestIndex = period;
+            pair<size_t, size_t> longestIndex = make_pair(retIndex, periodIndex);
             uint32_t longestPeriod = period.second - period.first;
             for(auto index : aroundIndexVec){
                 auto aroundPeriod = ret.at(index.first).periods.at(index.second);