assert len(indices) == len(self)

hello, When I use it, raise error: “assert len(indices) == len(self), f”{indices} not equal {len(self)} while offset is: {offset}“” then I print the length info, =====len of indices is 26865 - offset: 0 - len self 36650 below is the detail error info, Please help me. Traceback (most recent call last): File "tools/train.py", line 198, in <module> main() File "tools/train.py", line 193, in main meta=meta, File "/data6/ziqiwen/code/softteacher/ssod/apis/train.py", line 206, in train_detector runner.run(data_loaders, cfg.workflow) File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/mmcv/runner/iter_based_runner.py", line 117, in run iter_loaders = [IterLoader(x) for x in data_loaders] File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/mmcv/runner/iter_based_runner.py", line 117, in <listcomp> iter_loaders = [IterLoader(x) for x in data_loaders] File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/mmcv/runner/iter_based_runner.py", line 23, in __init__ self.iter_loader = iter(self._dataloader) File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 291, in __iter__ return _MultiProcessingDataLoaderIter(self) File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 764, in __init__ self._try_put_index() File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 994, in _try_put_index index = self._next_index() File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 357, in _next_index return next(self._sampler_iter) # may raise StopIteration File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/utils/data/sampler.py", line 208, in __iter__ for idx in self.sampler: File "/data6/ziqiwen/code/softteacher/ssod/datasets/samplers/semi_sampler.py", line 189, in __iter__ assert len(indices) == len(self) AssertionError Traceback (most recent call last): File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/runpy.py", line 193, in _run_module_as_main "__main__", mod_spec) File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/runpy.py", line 85, in _run_code exec(code, run_globals) File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/distributed/launch.py", line 261, in <module> main() File "/home/ziqiwen/anaconda3/envs/mm/lib/python3.7/site-packages/torch/distributed/launch.py", line 257, in main cmd=cmd)

[Jack-Hu-2001]

I guess the parametyer epoch_length is too small for your dataset since I encountered the same problem in my medical daataset weeks ago and solved this simply by turning it bigger. I haven’t carefully look at the sampler code so it’s just a simple and maybe unreasonable guess.

[MendelXu]

I am not sure what the problem is. I have tried to change the samplers_per_gpu to 4 like you, but it works well. I will take a deeper look later.