from keras import backend as K
from keras.engine.topology import Layer
class VariationalDropout(Layer):
def __init__(self, rate, noise_shape=None, seed=None, **kwargs):
super(VariationalDropout, self).__init__(**kwargs)
self.rate = min(1., max(0., rate))
self.noise_shape = noise_shape
self.seed = seed
self.supports_masking = True
def call(self, inputs, training=None):
if 0. < self.rate < 1.:
symbolic_shape = K.shape(inputs)
noise_shape = [shape if shape > 0 else symbolic_shape[axis]
for axis, shape in enumerate(self.noise_shape)]
noise_shape = tuple(noise_shape)
def dropped_inputs():
return K.dropout(inputs, self.rate, noise_shape, seed=self.seed)
return K.in_train_phase(dropped_inputs, inputs, training=training)
return inputs
def get_config(self):
config = {'rate': self.rate,
'noise_shape': self.noise_shape,
'seed': self.seed}
base_config = super(VariationalDropout, self).get_config()
return dict(list(base_config.items()) + list(config.items()))
