Fix the "Wrong future stop tick predictions" bug (#386)

lihuoran · web-flow · commit 790ed5543e3c · 2021-08-18T14:31:21.000+08:00
* Propose my new solution

Refine to the pre-process version

.

* Optimize import
diff --git a/maro/data_lib/cim/vessel_future_stops_prediction.py b/maro/data_lib/cim/vessel_future_stops_prediction.py
@@ -2,6 +2,7 @@
 # Licensed under the MIT license.
 
 from math import ceil
+from typing import List
 
 from .entities import CimBaseDataCollection, Stop
 
@@ -24,6 +25,7 @@ def __init__(self, data: CimBaseDataCollection):
         self._route_mapping = data.route_mapping
         self._port_mapping = data.port_mapping
         self._stop_number = data.future_stop_number
+        self._vessel_start_port_offsets = self._make_vessel_start_port_offset()
 
     def __getitem__(self, key):
         """Used to support querying future stops by vessel index, last location index, next location index."""
@@ -37,41 +39,40 @@ def __getitem__(self, key):
         # ignore current port if parking
         last_stop_idx = loc_idx + (0 if last_loc_idx == loc_idx else -1)
 
-        last_stop = self._stops[vessel_idx][last_stop_idx]
-        last_port_idx = last_stop.port_idx
-        last_port_arrival_tick = last_stop.arrival_tick
+        return self._predict_future_stops(vessel_idx, last_stop_idx, self._stop_number)
 
-        return self._predict_future_stops(vessel_idx, last_port_idx, last_port_arrival_tick, self._stop_number)
+    def _make_vessel_start_port_offset(self) -> List[int]:
+        vessel_start_port_offsets = []
+        for vessel in self._vessels:
+            route_points = self._routes[self._route_mapping[vessel.route_name]]
+            route_point_names = [rp.port_name for rp in route_points]
+            vessel_start_port_offset = route_point_names.index(vessel.start_port_name)
+            vessel_start_port_offsets.append(vessel_start_port_offset)
+        return vessel_start_port_offsets
 
-    def _predict_future_stops(self, vessel_idx: int, last_port_idx: int, last_port_arrival_tick: int, stop_number: int):
+    def _predict_future_stops(self, vessel_idx: int, last_stop_idx: int, stop_number: int):
         """Do predict future stops.
         """
         vessel = self._vessels[vessel_idx]
-        speed = vessel.sailing_speed
-        duration = vessel.parking_duration
-        route_name = vessel.route_name
-        route_points = self._routes[self._route_mapping[route_name]]
+        speed, duration = vessel.sailing_speed, vessel.parking_duration
+        route_points = self._routes[self._route_mapping[vessel.route_name]]
         route_length = len(route_points)
 
-        last_loc_idx = -1
-
-        # try to find the last location index from route
-        for loc_idx, route_point in enumerate(route_points):
-            if self._port_mapping[route_point.port_name] == last_port_idx:
-                last_loc_idx = loc_idx
-                break
+        last_stop = self._stops[vessel_idx][last_stop_idx]
+        last_port_arrival_tick = last_stop.arrival_tick
 
-        # return if not in current route
-        if last_loc_idx < 0:
-            return []
+        vessel_start_port_offset = self._vessel_start_port_offsets[vessel_idx]
+        last_loc_idx = (vessel_start_port_offset + last_stop_idx) % len(route_points)
 
         predicted_future_stops = []
         arrival_tick = last_port_arrival_tick
 
         # predict from configured sailing plan, not from stops
         for loc_idx in range(last_loc_idx + 1, last_loc_idx + stop_number + 1):
-            route_info = route_points[loc_idx % route_length]
-            port_idx, distance_to_next_port = self._port_mapping[route_info.port_name], route_info.distance_to_next_port
+            next_route_info = route_points[loc_idx % route_length]
+            last_route_info = route_points[(loc_idx - 1) % route_length]
+            port_idx = self._port_mapping[next_route_info.port_name]
+            distance_to_next_port = last_route_info.distance_to_next_port
 
             # NO noise for speed
             arrival_tick += duration + ceil(distance_to_next_port / speed)
diff --git a/maro/data_lib/cim/vessel_sailing_plan_wrapper.py b/maro/data_lib/cim/vessel_sailing_plan_wrapper.py
@@ -1,7 +1,7 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT license.
 
-from .entities import CimBaseDataCollection, Stop
+from .entities import CimBaseDataCollection
 from .vessel_future_stops_prediction import VesselFutureStopsPrediction
 
 
@@ -30,11 +30,6 @@ def __getitem__(self, key):
 
         route_length = len(self._routes[route_idx])
 
-        last_stop: Stop = self._stops[vessel_idx][next_loc_idx]
-        last_port_idx = last_stop.port_idx
-        last_port_arrival_tick = last_stop.arrival_tick
-
-        stops = self._predict_future_stops(
-            vessel_idx, last_port_idx, last_port_arrival_tick, route_length)
+        stops = self._predict_future_stops(vessel_idx, next_loc_idx, route_length)
 
         return [(stop.port_idx, stop.arrival_tick) for stop in stops]
