如果我有
self.model.add(LSTM(lstm1_size, input_shape=(seq_length, feature_dim), return_sequences=True))
self.model.add(BatchNormalization())
self.model.add(Dropout(0.2))
然后我的seq_length
指定我要一次处理多少个数据片。如果重要的话,我的模型是一个序列到序列(相同大小)。
但是如果我有:
self.model.add(Bidirectional(LSTM(lstm1_size, input_shape=(seq_length, feature_dim), return_sequences=True)))
self.model.add(BatchNormalization())
self.model.add(Dropout(0.2))
那是将序列大小加倍吗?还是在每个时间步长之前和之后都得到seq_length / 2
?
答案 0 :(得分:1)
使用双向LSTM层对序列长度没有影响。 我使用以下代码对此进行了测试:
from keras.models import Sequential
from keras.layers import Bidirectional,LSTM,BatchNormalization,Dropout,Input
model = Sequential()
lstm1_size = 50
seq_length = 128
feature_dim = 20
model.add(Bidirectional(LSTM(lstm1_size, input_shape=(seq_length, feature_dim), return_sequences=True)))
model.add(BatchNormalization())
model.add(Dropout(0.2))
batch_size = 32
model.build(input_shape=(batch_size,seq_length, feature_dim))
model.summary()
这导致双向输出如下
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
bidirectional_1 (Bidirection (32, 128, 100) 28400
_________________________________________________________________
batch_normalization_1 (Batch (32, 128, 100) 400
_________________________________________________________________
dropout_1 (Dropout) (32, 128, 100) 0
=================================================================
Total params: 28,800
Trainable params: 28,600
Non-trainable params: 200
没有双向层:
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
lstm_1 (LSTM) (None, 128, 50) 14200
_________________________________________________________________
batch_normalization_1 (Batch (None, 128, 50) 200
_________________________________________________________________
dropout_1 (Dropout) (None, 128, 50) 0
=================================================================
Total params: 14,400
Trainable params: 14,300
Non-trainable params: 100
_________________________________________________________________