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from core.leras import nn |
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tf = nn.tf |
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class BatchNorm2D(nn.LayerBase): |
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""" |
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currently not for training |
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""" |
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def __init__(self, dim, eps=1e-05, momentum=0.1, dtype=None, **kwargs): |
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self.dim = dim |
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self.eps = eps |
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self.momentum = momentum |
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if dtype is None: |
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dtype = nn.floatx |
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self.dtype = dtype |
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super().__init__(**kwargs) |
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def build_weights(self): |
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self.weight = tf.get_variable("weight", (self.dim,), dtype=self.dtype, initializer=tf.initializers.ones() ) |
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self.bias = tf.get_variable("bias", (self.dim,), dtype=self.dtype, initializer=tf.initializers.zeros() ) |
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self.running_mean = tf.get_variable("running_mean", (self.dim,), dtype=self.dtype, initializer=tf.initializers.zeros(), trainable=False ) |
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self.running_var = tf.get_variable("running_var", (self.dim,), dtype=self.dtype, initializer=tf.initializers.zeros(), trainable=False ) |
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def get_weights(self): |
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return [self.weight, self.bias, self.running_mean, self.running_var] |
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def forward(self, x): |
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if nn.data_format == "NHWC": |
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shape = (1,1,1,self.dim) |
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else: |
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shape = (1,self.dim,1,1) |
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weight = tf.reshape ( self.weight , shape ) |
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bias = tf.reshape ( self.bias , shape ) |
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running_mean = tf.reshape ( self.running_mean, shape ) |
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running_var = tf.reshape ( self.running_var , shape ) |
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x = (x - running_mean) / tf.sqrt( running_var + self.eps ) |
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x *= weight |
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x += bias |
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return x |
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nn.BatchNorm2D = BatchNorm2D |