写一维胶囊网络的代码keras并训练
时间: 2024-03-13 07:43:58 浏览: 156
胶囊网络代码
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好的,下面是一维胶囊网络的Keras代码和训练:
```python
from keras import layers, models
# 定义胶囊层
class CapsuleLayer(layers.Layer):
def __init__(self, num_capsule, dim_capsule, routings=3, **kwargs):
super(CapsuleLayer, self).__init__(**kwargs)
self.num_capsule = num_capsule
self.dim_capsule = dim_capsule
self.routings = routings
def build(self, input_shape):
assert len(input_shape) >= 3
self.input_num_capsule = input_shape[-2]
self.input_dim_capsule = input_shape[-1]
self.W = self.add_weight(shape=(self.input_num_capsule, self.num_capsule, self.input_dim_capsule, self.dim_capsule), initializer='glorot_uniform', name='W')
self.built = True
def call(self, inputs, training=None):
inputs_expand = K.expand_dims(inputs, 2)
inputs_tiled = K.tile(inputs_expand, [1, 1, self.num_capsule, 1])
inputs_hat = K.map_fn(lambda x: K.batch_dot(x, self.W, [2, 3]), elems=inputs_tiled)
b = tf.zeros(shape=[K.shape(inputs_hat)[0], self.input_num_capsule, self.num_capsule])
for i in range(self.routings):
c = tf.nn.softmax(b, axis=2)
outputs = squash(K.batch_dot(c, inputs_hat, [2, 2]))
if i < self.routings - 1:
b += K.batch_dot(outputs, inputs_hat, [2, 3])
return outputs
def compute_output_shape(self, input_shape):
return (None, self.num_capsule, self.dim_capsule)
# 定义Squash函数
def squash(x, axis=-1):
s_squared_norm = K.sum(K.square(x), axis, keepdims=True)
scale = K.sqrt(s_squared_norm + K.epsilon())
return x / scale
# 定义模型
def CapsuleNetwork(input_shape, n_class, num_capsule, dim_capsule, routings):
x = layers.Input(shape=input_shape)
# 第一层卷积和池化
conv1 = layers.Conv1D(filters=256, kernel_size=9, strides=1, padding='valid', activation='relu', name='conv1')(x)
primarycaps = PrimaryCapsule(conv1, dim_capsule, num_capsule)
# 第二层胶囊网络
digitcaps = CapsuleLayer(num_capsule=n_class, dim_capsule=dim_capsule, routings=routings, name='digitcaps')(primarycaps)
# 输出层
out_caps = layers.Lambda(lambda x: K.sqrt(K.sum(K.square(x), 2)), name='out_caps')(digitcaps)
y = layers.Input(shape=(n_class,))
masked_by_y = Mask()([digitcaps, y])
masked = Mask()(digitcaps)
# Margin loss
L = layers.Lambda(lambda x: K.sum(x, 1), name='L')(masked_by_y)
# 构建模型
model = models.Model([x, y], [out_caps, L])
return model
# 定义PrimaryCapsule层
def PrimaryCapsule(inputs, dim_capsule, n_channels, kernel_size=9, strides=2, padding='valid'):
output = layers.Conv1D(filters=dim_capsule*n_channels, kernel_size=kernel_size, strides=strides, padding=padding, name='primarycaps_conv')(inputs)
outputs = layers.Reshape(target_shape=[-1, dim_capsule], name='primarycaps_reshape')(output)
return layers.Lambda(squash, name='primarycaps_squash')(outputs)
# 定义Mask层
class Mask(layers.Layer):
def call(self, inputs, **kwargs):
if type(inputs) is list:
assert len(inputs) == 2
inputs, mask = inputs
else:
x = tf.sqrt(tf.reduce_sum(tf.square(inputs), -1))
mask = tf.one_hot(tf.argmax(x, 1), inputs.get_shape().as_list()[1])
masked = K.batch_flatten(inputs * K.expand_dims(mask, -1))
return masked
def compute_output_shape(self, input_shape):
if type(input_shape[0]) is tuple:
return tuple([None, input_shape[0][-1] * input_shape[1][-1]])
else:
return tuple([None, input_shape[-1]])
# 训练模型
model = CapsuleNetwork(input_shape=(784, 1), n_class=10, num_capsule=10, dim_capsule=16, routings=3)
model.summary()
model.compile(optimizer='adam', loss=['mse', 'mae'], loss_weights=[0.5, 0.5], metrics={'out_caps': 'accuracy'})
model.fit([x_train, y_train], [y_train, y_train], batch_size=128, epochs=50, validation_data=[[x_test, y_test], [y_test, y_test]])
```
其中,`CapsuleLayer` 定义了胶囊层,`PrimaryCapsule` 定义了 PrimaryCapsule 层,`Mask` 定义了 mask 层。`CapsuleNetwork` 定义了整个模型,其中包括卷积层、PrimaryCapsule 层、胶囊层和输出层。最后通过 `model.fit()` 函数进行训练。
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