utils_tf.py 文件源码

def l2_batch_normalize(x, epsilon=1e-12, scope=None):
    """
    Helper function to normalize a batch of vectors.
    :param x: the input placeholder
    :param epsilon: stabilizes division
    :return: the batch of l2 normalized vector
    """
    with tf.name_scope(scope, "l2_batch_normalize") as scope:
        x_shape = tf.shape(x)
        x = tf.contrib.layers.flatten(x)
        x /= (epsilon + tf.reduce_max(tf.abs(x), 1, keep_dims=True))
        square_sum = tf.reduce_sum(tf.square(x), 1, keep_dims=True)
        x_inv_norm = tf.rsqrt(np.sqrt(epsilon) + square_sum)
        x_norm = tf.multiply(x, x_inv_norm)
        return tf.reshape(x_norm, x_shape, scope)