51 lines
1.5 KiB
Python
51 lines
1.5 KiB
Python
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from torch.utils.data.dataset import ConcatDataset as _ConcatDataset
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from .builder import DATASETS
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@DATASETS.register_module()
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class ConcatDataset(_ConcatDataset):
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"""A wrapper of concatenated dataset.
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Same as :obj:`torch.utils.data.dataset.ConcatDataset`, but
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concat the group flag for image aspect ratio.
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Args:
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datasets (list[:obj:`Dataset`]): A list of datasets.
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"""
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def __init__(self, datasets):
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super(ConcatDataset, self).__init__(datasets)
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self.CLASSES = datasets[0].CLASSES
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self.PALETTE = datasets[0].PALETTE
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@DATASETS.register_module()
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class RepeatDataset(object):
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"""A wrapper of repeated dataset.
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The length of repeated dataset will be `times` larger than the original
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dataset. This is useful when the data loading time is long but the dataset
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is small. Using RepeatDataset can reduce the data loading time between
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epochs.
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Args:
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dataset (:obj:`Dataset`): The dataset to be repeated.
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times (int): Repeat times.
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"""
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def __init__(self, dataset, times):
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self.dataset = dataset
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self.times = times
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self.CLASSES = dataset.CLASSES
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self.PALETTE = dataset.PALETTE
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self._ori_len = len(self.dataset)
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def __getitem__(self, idx):
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"""Get item from original dataset."""
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return self.dataset[idx % self._ori_len]
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def __len__(self):
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"""The length is multiplied by ``times``"""
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return self.times * self._ori_len
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