test mergemulti traj at one place

apps/function/multi_traj_functions.cpp

@@ -220,11 +220,11 @@ void filterByPosition(
                     }
                 }
             }
-            pair<size_t, size_t> longestIndex;
-            uint32_t longestPeriod = 0;
+            pair<size_t, size_t> longestIndex = period;
+            uint32_t longestPeriod = period.second - period.first;
             for(auto index : aroundIndexVec){
-                auto period = ret.at(index.first).periods.at(index.second);
-                uint32_t periodDuration = period.second - period.first;
+                auto aroundPeriod = ret.at(index.first).periods.at(index.second);
+                uint32_t periodDuration = aroundPeriod.second - aroundPeriod.first;
                 if(periodDuration > longestPeriod){
                     longestPeriod = periodDuration;
                     longestIndex = index;