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kerasmatrix-multiplication

Dotproduct in keras causes AttributeError: 'NoneType' object has no attribute '_inbound_nodes' error

I'm trying to do matmul inside the keras graph and got AttributeError: 'NoneType' object has no attribute '_inbound_nodes' error when compiling the model

from keras import backend as K
from keras.layers import Input, Dense, Reshape

mainInput = Input(shape=(10*10,))
x = Dense(10*10, activation='relu')(x)
x1 =  Reshape((10, 10))(x)
x2 = Dense( 2 * 10, activation='relu')(x)
x2 =  Reshape((2, 10))(x2)
added = K.dot(x2, x1)
out = Dense(2 * 10, activation='linear')(added)
optimizer = optimizers.adam(lr=0.001)
model = Model(inputs=[mainInput], outputs=[out])
model.compile(loss='mse', metrics = ['mae'], optimizer=optimizer)

What is the reason of this error?

Solution

  • All operations must be inside keras layers:

    added = Lambda(lambda x: K.dot(x[1],x[0]))([x1,x2])

    I think your Reshape will fail, because you're trying to reshape (None, 10, 20) into (None, 2, 10).