models.py 文件源码

def loss(logits, labels):
    batch_size = tf.size(labels)
    labels = tf.expand_dims(labels, 1)
    indices = tf.expand_dims(tf.range(0, batch_size, 1), 1)
    concated = tf.concat(axis=1, values=[indices, labels])
    onehot_labels = tf.sparse_to_dense(
        concated, tf.stack([batch_size, 1000]), 1.0, 0.0)
    cross_entropy = tf.nn.softmax_cross_entropy_with_logits(logits=logits,
                                                            labels=onehot_labels,
                                                            name='xentropy')
    loss = tf.reduce_mean(cross_entropy, name='xentropy_mean')
    return loss