如何将整个keras模型转换为theano函数

我想将我的keras模型转换为theano函数，以便我可以计算输入上的梯度。我认为这对于可视化网络可能很酷。我想使用这些渐变来增强原始图像中基于神经网络认为它们的特征。我不明白我在做什么错了下面的代码。如何将整个keras模型转换为theano函数

model = Sequential() 
model.add(InputLayer((3, H, W))) 
model.add(GaussianNoise(0.03)) 

model.add(Flatten()) 
model.add(Dense(512, activation = 'relu', name = 'dense')) 
model.add(Dropout(0.2)) 
model.add(Dense(20, activation = 'relu')) 
model.add(Dense(C, activation = 'softmax', W_regularizer = l2())) 
... 
f = theano.function([model.input], model.output)

我收到以下异常。

theano.gof.fg.MissingInputError: A variable that is an input to the graph was neither provided as an input to the function nor given a value. A chain of variables leading from this input to an output is [keras_learning_phase, DimShuffle{x,x}.0, Elemwise{switch,no_inplace}.0, dot.0, Elemwise{add,no_inplace}.0, Elemwise{add,no_inplace}.0, Elemwise{mul,no_inplace}.0, dot.0, Elemwise{add,no_inplace}.0, Softmax.0]. This chain may not be unique 
Backtrace when the variable is created: 
    File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed 
    File "/usr/local/lib/python3.5/dist-packages/keras/backend/__init__.py", line 51, in <module> 
    from .theano_backend import * 
    File "<frozen importlib._bootstrap>", line 969, in _find_and_load 
    File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked 
    File "<frozen importlib._bootstrap>", line 673, in _load_unlocked 
    File "<frozen importlib._bootstrap_external>", line 662, in exec_module 
    File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed 
    File "/usr/local/lib/python3.5/dist-packages/keras/backend/theano_backend.py", line 13, in <module> 
    _LEARNING_PHASE = T.scalar(dtype='uint8', name='keras_learning_phase') # 0 = test, 1 = train

来源

2016-05-14 chasep255

继FAQ，请尝试：

from keras import backend as K 
get_last_layer_output = K.function([model.layers[0].input], 
            [model.layers[-1].output])

有关最新版本Keras（1.0），使用

from keras import backend as K 
get_last_layer_output = K.function([model.layers[0].input], 
            [model.layers[-1].get_output(train=False)])

来源

2016-05-14 08:47:52

对于 “老” keras（0.3.X，例如）：

我不使用这个版本，但像this one这样的例子应该可以工作。

对于 “新” keras（1.0+）：（0测试，1培训）

由于您使用Dropout层，你将需要添加其他输入K.learning_phase()并给它的值为0

代码：

from keras import backend as K 
K.function([model.layers[0].input, K.learning_phase()], [model.layers[-1].output])

参考：keras FAQ

来源

2016-06-08 11:42:05 sytrus

如何将整个keras模型转换为theano函数

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