Wrong prediction in future stop list in CIM scenario 🐛

Description

While estimating future vessel stops in VesselFutureStopsPrediction there is a bug in the starting point when last_loc_idx == next_loc_idx.

In particular, when the previous condition is satisfied, the predictions retrieved by VesselFutureStopsPrediction._predict_future_stops() are one step ahead.

Screenshots

To Reproduce

To reproduce the behavior, just run the following snippet of code.

from maro.backends.frame import SnapshotList
from maro.simulator import Env
from pprint import pprint
from typing import List
import numpy as np

# Initialize an Env for CIM scenario
env = Env(scenario="cim", topology="toy.4p_ssdd_l0.0", start_tick=0, durations=1120)
    
# Start the environment with None action
_, event, is_done = env.step(None)

while not is_done:
    metrics, event, is_done = env.step(None)

vessel_snapshots = env.snapshot_list["vessels"]
print(vessel_snapshots[[i for i in range(0, 20)]:2:['future_stop_list', 'future_stop_tick_list', 'last_loc_idx']].reshape(20, 7))

For toy.4p_ssdd_l0.0 vessel arrivals happen every 7 steps. You can see that when at t such that t % 7 == 0, predictions will jump one step ahead.

Expected Behavior

When last_loc_idx == next_loc_idx predictions should not be 1-step ahead.

Environment

• MARO version (e.g., v0.1.1a1): master
• MARO scenario (CIM, Citi Bike): CIM
• MARO component (Simulation, RL, Distributed Training): Simulation
• Orchestration platform (GraSS on Azure, AKS on Azure):
• How you installed MARO (pip, source): source
• OS (Linux, Windows, macOS): Linux
• Python version (3.6, 3.7): 3.7
• Docker image (e.g., arthursjiang/maro:cpu[5f36ed]):
• CPU/GPU:
• Any other relevant information:

Additional Context

[riccardopoiani]

Hi @Jinyu-W thanks very much for the fix. Seems to be working to me 😃

I’ll let you know if I’ll find some other problems in the future. For now, I consider this issue closed.

[Jinyu-W]

Hi @riccardopoiani , we’ve added the parking port idx into the vessel in PR #366, please check the master branch and try the attributes below:

        is_parking    # Is parking or not, 1 means parking, 0 means sailing.
        loc_port_idx  # The port index the vessel is parking at.