tf_util.py 文件源码

def batchnorm(x, name, phase, updates, gamma=0.96):
    k = x.get_shape()[1]
    runningmean = tf.get_variable(name+"/mean", shape=[1, k], initializer=tf.constant_initializer(0.0), trainable=False)
    runningvar = tf.get_variable(name+"/var", shape=[1, k], initializer=tf.constant_initializer(1e-4), trainable=False)
    testy = (x - runningmean) / tf.sqrt(runningvar)

    mean_ = mean(x, axis=0, keepdims=True)
    var_ = mean(tf.square(x), axis=0, keepdims=True)
    std = tf.sqrt(var_)
    trainy = (x - mean_) / std

    updates.extend([
        tf.assign(runningmean, runningmean * gamma + mean_ * (1 - gamma)),
        tf.assign(runningvar, runningvar * gamma + var_ * (1 - gamma))
    ])

    y = switch(phase, trainy, testy)

    out = y * tf.get_variable(name+"/scaling", shape=[1, k], initializer=tf.constant_initializer(1.0), trainable=True)\
            + tf.get_variable(name+"/translation", shape=[1,k], initializer=tf.constant_initializer(0.0), trainable=True)
    return out

# ================================================================
# Mathematical utils
# ================================================================