顺序层的输入 0 与预期 ndim=3 的层不兼容，发现 ndim=2。已收到完整形状：[None, 1]

Question

我正在使用 keras 进行文本分类。经过预处理和矢量化后，我的训练和验证数据详细信息如下所示：

print(X_train.shape, ',', X_train.ndim, ',', type(X_train))
print(y_train.shape, ',', y_train.ndim, ',', type(y_train))
print(X_valid.shape, ',', X_valid.ndim, ',', type(X_valid))
print(y_valid.shape, ',', y_valid.ndim, ',', type(y_valid))
print(data_dim)

输出为：

(14904,) , 1 , <class 'numpy.ndarray'>
(14904,) , 1 , <class 'numpy.ndarray'>
(3725,) , 1 , <class 'numpy.ndarray'>
(3725,) , 1 , <class 'numpy.ndarray'>
15435

则模型定义为：

model = Sequential()
model.add(LSTM(100, input_shape=(data_dim,1 ), return_sequences=True))
model.add(Dropout(0.2))
model.add(LSTM(200))
model.add(Dropout(0.2))
model.add(Dense(1, activation='sigmoid'))

model.compile(loss='binary_crossentropy', optimizer='adam', metrics = ['accuracy'])
model.summary()

模型摘要：

模型拟合：

model.fit(X_train,y_train, validation_data = (X_valid, y_valid),
          batch_size=batch_size, epochs=epochs)

为什么会出现这个错误？

----> 1 model.fit(X_train,y_train, validation_data = (X_valid, y_valid),
      2           batch_size=batch_size, epochs=epochs)
...
...

    ValueError: Input 0 of layer sequential is incompatible with the layer:
              expected ndim=3, found ndim=2. Full shape received: [None, 1]

Answer 1

终于在this kaggle notebook的帮助下克服了这个问题。

我将数据维度更改为：

print(X_train.shape)
print(y_train.shape)
print(X_valid.shape)
print(y_valid.shape)
print(X_test.shape)
print(y_test.shape)
print(data_dim)
########################## output ###########################
(14904, 15435)
(14904,)
(3725, 15435)
(3725,)
(5686, 15435)
(5686,)
15435

然后将数据重塑为：

X_train = np.reshape(X_train, (X_train.shape[0], 1, X_train.shape[1]))
X_valid = np.reshape(X_valid, (X_valid.shape[0], 1, X_valid.shape[1]))
X_test = np.reshape(X_test, (X_test.shape[0], 1, X_test.shape[1]))
########################## output ###########################
(14904, 1, 15435)
(3725, 1, 15435)
(5686, 1, 15435)

最后把LSTMinput_shape改成：

model.add(LSTM(units=50, input_shape=(1, data_dim), return_sequences=True))

现在，模型摘要为：

现在没有问题，model.fit 执行正常。

顺序层的输入 0 与预期 ndim=3 的层不兼容，发现 ndim=2。已收到完整形状：[None, 1]

Input 0 of layer sequential is incompatible with the layer expected ndim=3, found ndim=2. Full shape received: [None, 1]

python

model-fitting

keras

tensorflow