input_search and target_search are unchanged during iteration

[yukang2017]

darts/cnn/train_search.py

Line 147 in b6d4fe1

input_search, target_search = next(iter(search_queue))

Hi, thank you for releasing code! nice work!
But I discover something I can't understand. In function train in train_search.py, input_search and target_search are unchanged during iteration. They are always the first batch in search_queue.

Is it a small bug or you do it by purpose?

[yukang2017]

I guess this part should be:

it = iter(search_queue)
for step, (input, target) in enumerate(train_queue):
...
input_search, target_search = next(it)
...

[quark0]

This is not a bug. The "first batch" returned by next(iter(search_queue)) is supposed to be different in each step as search_queue is based on SubsetRandomSampler. Can you double check by printing the batch per step? This was done by purpose to prevent search_queue from running out of data during a training epoch (which could happen if the search set is smaller than the training set).

[yukang2017]

Sorry, I was wrong.

[quark0]

No worries and thanks for helping inspect the code. I'll put a comment there in my next commit.

[JaminFong]

@quark0 Hello~I find that doing like this equals to sampling with replacement. It will cause repeated samples in one epoch. And the samples in the validation set cannot be traversed in one epoch.

darts/cnn/train_search.py

Line 143 in f276dd3

input_search, target_search = next(iter(valid_queue))

[ShihuaHuang95]

@JaminFong And any suggestions?