metrics.py 文件源码

def perplexity(label, logit):
    words = tf.cast(tf.size(label), tf.float32)
    cross_entropy = tf.nn.sparse_softmax_cross_entropy_with_logits(labels=label, logits=logit)
    cross_entropy = tf.divide(tf.reduce_sum(cross_entropy), words)
    perplex = tf.pow(2.0, cross_entropy)
    return perplex