Question about the ADE in metrics.py

[MeimingWang]

Hi, thanks for sharing your codes. You have done a great job. But I have a question about the ADE in the codes:

constant_velocity_pedestrian_motion/metrics.py

Lines 4 to 15 in 7fe0716

	def avg_disp(y_pred, y_true):
	""" Average displacement error. """
	y_true, masks = y_true
	seq_lengths = masks.sum(1)
	batch_size = len(seq_lengths)
	squared_dist = (y_true - y_pred)**2
	l2_dist = masks * torch.sqrt(squared_dist.sum(2))
	avg_l2_dist = (1./batch_size) * ((1./seq_lengths) * l2_dist.sum(1)).sum()
	return avg_l2_dist.item()

avg_l2_dist = (1./batch_size) * ((1./seq_lengths) * l2_dist.sum(1)).sum()
Why do you still multiply 1./batch_size while you have already multiplied 1./seq_lengths. I can't figure out the reason. Let's assume that all the positions in the predicted trajectory are valid, which means seq_legths = 12 and batch_size = 12. So in your code, you divide the l2_dist.sum(1) by 12*12. I think the right way is to divide it by 12. Could you tell me the reason why you do that?

[MeimingWang]

After running the codes, I find that I was wrong. batch_size = 1 not 12 in final result. Anyway, thanks for your sharing!