我定义了一个自定义Dataset
和一个自定义Dataloader
,我想使用for i,batch in enumerate(loader)
访问所有批处理。但是这个for循环在每个历元中给了我不同的批数,并且它们都远远小于实际的批数(等于number_of_samples/batch_size
)
以下是我如何定义数据集和数据加载器:
class UsptoDataset(Dataset):
def __init__(self, csv_file):
df = pd.read_csv(csv_file)
self.rea_trees = df['reactants_trees'].to_numpy()
self.syn_trees = df['synthons_trees'].to_numpy()
self.syn_smiles = df['synthons'].to_numpy()
self.product_smiles = df['product'].to_numpy()
def __len__(self):
return len(self.rea_trees)
def __getitem__(self, item):
rea_tree = self.rea_trees[item]
syn_tree = self.syn_trees[item]
syn_smile = self.syn_smiles[item]
pro_smile = self.product_smiles[item]
# omit the snippet used to process the data here, which gives us the variables used in the return statement.
return {'input_words': input_words,
'input_chars': input_chars,
'syn_tree_indices': syn_tree_indices,
'syn_rule_nl_left': syn_rule_nl_left,
'syn_rule_nl_right': syn_rule_nl_right,
'rea_tree_indices': rea_tree_indices,
'rea_rule_nl_left': rea_rule_nl_left,
'rea_rule_nl_right': rea_rule_nl_right,
'class_mask': class_mask,
'query_paths': query_paths,
'labels': labels,
'parent_matrix': parent_matrix,
'syn_parent_matrix': syn_parent_matrix,
'path_lens': path_lens,
'syn_path_lens': syn_path_lens}
@staticmethod
def collate_fn(batch):
input_words = torch.tensor(np.stack([_['input_words'] for _ in batch], axis=0), dtype=torch.long)
input_chars = torch.tensor(np.stack([_['input_chars'] for _ in batch], axis=0), dtype=torch.long)
syn_tree_indices = torch.tensor(np.stack([_['syn_tree_indices'] for _ in batch], axis=0), dtype=torch.long)
syn_rule_nl_left = torch.tensor(np.stack([_['syn_rule_nl_left'] for _ in batch], axis=0), dtype=torch.long)
syn_rule_nl_right = torch.tensor(np.stack([_['syn_rule_nl_right'] for _ in batch], axis=0), dtype=torch.long)
rea_tree_indices = torch.tensor(np.stack([_['rea_tree_indices'] for _ in batch], axis=0), dtype=torch.long)
rea_rule_nl_left = torch.tensor(np.stack([_['rea_rule_nl_left'] for _ in batch], axis=0), dtype=torch.long)
rea_rule_nl_right = torch.tensor(np.stack([_['rea_rule_nl_right'] for _ in batch], axis=0), dtype=torch.long)
class_mask = torch.tensor(np.stack([_['class_mask'] for _ in batch], axis=0), dtype=torch.float32)
query_paths = torch.tensor(np.stack([_['query_paths'] for _ in batch], axis=0), dtype=torch.long)
labels = torch.tensor(np.stack([_['labels'] for _ in batch], axis=0), dtype=torch.long)
parent_matrix = torch.tensor(np.stack([_['parent_matrix'] for _ in batch], axis=0), dtype=torch.float)
syn_parent_matrix = torch.tensor(np.stack([_['syn_parent_matrix'] for _ in batch], axis=0), dtype=torch.float)
path_lens = torch.tensor(np.stack([_['path_lens'] for _ in batch], axis=0), dtype=torch.long)
syn_path_lens = torch.tensor(np.stack([_['syn_path_lens'] for _ in batch], axis=0), dtype=torch.long)
return_dict = {'input_words': input_words,
'input_chars': input_chars,
'syn_tree_indices': syn_tree_indices,
'syn_rule_nl_left': syn_rule_nl_left,
'syn_rule_nl_right': syn_rule_nl_right,
'rea_tree_indices': rea_tree_indices,
'rea_rule_nl_left': rea_rule_nl_left,
'rea_rule_nl_right': rea_rule_nl_right,
'class_mask': class_mask,
'query_paths': query_paths,
'labels': labels,
'parent_matrix': parent_matrix,
'syn_parent_matrix': syn_parent_matrix,
'path_lens': path_lens,
'syn_path_lens': syn_path_lens}
return return_dict
train_dataset=UsptoDataset("train_trees.csv")
train_loader = DataLoader(train_dataset, batch_size=4, shuffle=True, num_workers=1, collate_fn=UsptoDataset.collate_fn)
当我按如下方式使用dataloader时,它会给我每个历元不同的批数:
epoch_steps = len(train_loader)
for e in range(epochs):
for j, batch_data in enumerate(train_loader):
step = e * epoch_steps + j
日志显示第一个历元只有5个批次,第二个历元有3个批次,第三个历元有5个批次,依此类推
1 Config:
2 Namespace(batch_size_per_gpu=4, epochs=400, eval_every_epoch=1, hidden_size=128, keep=10, log_every_step=1, lr=0.001, new_model=False, save_dir='saved_model/', workers=1)
3 2021-01-06 15:33:17,909 - __main__ - WARNING - Checkpoints not found in dir saved_model/, creating a new model.
4 2021-01-06 15:33:18,340 - __main__ - INFO - Step: 0, Loss: 5.4213, Rule acc: 0.1388
5 2021-01-06 15:33:18,686 - __main__ - INFO - Step: 1, Loss: 4.884, Rule acc: 0.542
6 2021-01-06 15:33:18,941 - __main__ - INFO - Step: 2, Loss: 4.6205, Rule acc: 0.6122
7 2021-01-06 15:33:19,174 - __main__ - INFO - Step: 3, Loss: 4.4442, Rule acc: 0.61
8 2021-01-06 15:33:19,424 - __main__ - INFO - Step: 4, Loss: 4.3033, Rule acc: 0.6211
9 2021-01-06 15:33:20,684 - __main__ - INFO - Dev Loss: 3.5034, Dev Sample Acc: 0.0, Dev Rule Acc: 0.5970844200679234, in epoch 0
10 2021-01-06 15:33:22,203 - __main__ - INFO - Test Loss: 3.4878, Test Sample Acc: 0.0, Test Rule Acc: 0.6470248053471247
11 2021-01-06 15:33:22,394 - __main__ - INFO - Found better dev sample accuracy 0.0 in epoch 0
12 2021-01-06 15:33:22,803 - __main__ - INFO - Step: 10002, Loss: 3.6232, Rule acc: 0.6555
13 2021-01-06 15:33:23,046 - __main__ - INFO - Step: 10003, Loss: 3.53, Rule acc: 0.6442
14 2021-01-06 15:33:23,286 - __main__ - INFO - Step: 10004, Loss: 3.4907, Rule acc: 0.6498
15 2021-01-06 15:33:24,617 - __main__ - INFO - Dev Loss: 3.3081, Dev Sample Acc: 0.0, Dev Rule Acc: 0.5980878387178693, in epoch 1
16 2021-01-06 15:33:26,215 - __main__ - INFO - Test Loss: 3.2859, Test Sample Acc: 0.0, Test Rule Acc: 0.6466992994149526
17 2021-01-06 15:33:26,857 - __main__ - INFO - Step: 20004, Loss: 3.3965, Rule acc: 0.6493
18 2021-01-06 15:33:27,093 - __main__ - INFO - Step: 20005, Loss: 3.3797, Rule acc: 0.6314
19 2021-01-06 15:33:27,353 - __main__ - INFO - Step: 20006, Loss: 3.3959, Rule acc: 0.5727
20 2021-01-06 15:33:27,609 - __main__ - INFO - Step: 20007, Loss: 3.3632, Rule acc: 0.6279
21 2021-01-06 15:33:27,837 - __main__ - INFO - Step: 20008, Loss: 3.3331, Rule acc: 0.6158
22 2021-01-06 15:33:29,122 - __main__ - INFO - Dev Loss: 3.0911, Dev Sample Acc: 0.0, Dev Rule Acc: 0.6016287207603455, in epoch 2
23 2021-01-06 15:33:30,689 - __main__ - INFO - Test Loss: 3.0651, Test Sample Acc: 0.0, Test Rule Acc: 0.6531393428643545
24 2021-01-06 15:33:32,143 - __main__ - INFO - Dev Loss: 3.0911, Dev Sample Acc: 0.0, Dev Rule Acc: 0.6016287207603455, in epoch 3
25 2021-01-06 15:33:33,765 - __main__ - INFO - Test Loss: 3.0651, Test Sample Acc: 0.0, Test Rule Acc: 0.6531393428643545
26 2021-01-06 15:33:34,359 - __main__ - INFO - Step: 40008, Loss: 3.108, Rule acc: 0.6816
27 2021-01-06 15:33:34,604 - __main__ - INFO - Step: 40009, Loss: 3.0756, Rule acc: 0.6732
28 2021-01-06 15:33:35,823 - __main__ - INFO - Dev Loss: 3.0419, Dev Sample Acc: 0.0, Dev Rule Acc: 0.613776079245976, in epoch 4
仅供参考,len(train_loader.dataset)
、batch_size
和len(train_loader)
的值分别是40008
、4
和10002
,这正是我所期望的。因此,使用enumerate
只会给我几个批,比如3
或5
(10002
是预期的),这是非常令人困惑的
我不确定你的代码有什么问题。据我所知,您在
collate_fn
中试图做的是从批处理中收集并堆叠相同特征类型的数据。比如:您正在使用和{}键。在我的示例中,我们将仅使用
input_words
、input_chars
、syn_tree_indices
、syn_rule_nl_left
、syn_rule_nl_left
、syn_rule_nl_right
、rea_tree_indices
、rea_tree_indices
、rea_rule_nl_left
、rea_rule_nl_right
、class_mask
、query_paths
、labels
、syn_parent_matrix
、^a
、b
、c
和d
保持简单__getitem__
将从数据集中返回单个数据点。在你和我们的例子中,这将是一个词汇表:{'a': ..., 'b': ..., 'c': ..., 'd': ...}
collate_fn
:返回数据时,是数据集和数据加载器之间的中间层。它获取批处理元素的列表(使用__getitem__
逐个收集的元素)。您要返回的是经过整理的批次。将[{'a': ..., 'b': ..., 'c': ..., 'd': ...}, ...]
转换成{'a': [...], 'b': [...], 'c': [...], 'd': [...]}
的东西。其中'a'
键将包含来自a
功能的所有数据现在您可能不知道的是,对于这种简单类型的排序,您实际上不需要
collate_fn
。我相信元组和词汇表是由PyTorch数据加载程序自动处理的。这意味着如果您从__getitem__
返回一个字典,您的数据加载器将自动按键进行排序这里,还是我们最简单的例子:
正如您在下面的打印中所看到的,数据是通过键收集的
提供
collate_fn
参数将删除此自动校对相关问题 更多 >
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