get_frame_indices issue

[JeffreyWardman]

In agent_motion_prediction.ipynb:
The below seems to only work with valuse -51 to -23348 (with indices capped at -23846)
agent_indices = eval_agent_dataset.get_frame_indices(frame_number) .

A quick inspection shows that in agent.py:

self.agents_indices has values with max:1795829, min:33543, shape:(13985,) yet agents_start_index and agents_end_index are 0 and 37 respectively (frames[frame_idx]["agent_index_interval"] = array([0, 38]))
Hence there will be no valid indices and the below will return an empty array:

    def get_frame_indices(self, frame_idx: int) -> np.ndarray:
        """
        Get indices for the given frame. Here __getitem__ iterate over valid agents indices.
        This means ``__getitem__(0)`` matches the first valid agent in the dataset.
        Args:
            frame_idx (int): index of the scene

        Returns:
            np.ndarray: indices that can be used for indexing with __getitem__
        """
        frames = self.dataset.frames
        assert frame_idx < len(frames), f"frame_idx {frame_idx} is over len {len(frames)}"

        agents_start_index = frames[frame_idx]["agent_index_interval"][0]
        agents_end_index = frames[frame_idx]["agent_index_interval"][1] - 1

        mask_valid_indices = (self.agents_indices >= agents_start_index) * (self.agents_indices <= agents_end_index)
        indices = np.nonzero(mask_valid_indices)[0]
        return indices

I'm unfamiliar with the code but the get_frame_indices in the parent class is different to that in the AgentDataset class.

[lucabergamini]

This should be related to #38 . val_data_loader/datasets/scene_indices set to 0 means only the first scene was taken for validation.

I've started #40 that also address the visualisation issue to ensure a frame with agents is always taken. Let me know if this addresses your concerns.

[JeffreyWardman]

@lucabergamini great, thanks!

[lucabergamini]

#40 has been merged. Let me know if you still see the issue after pulling master again. I'll close for now