> For the complete documentation index, see [llms.txt](https://baozoulin.gitbook.io/neural-networks-and-deep-learning/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://baozoulin.gitbook.io/neural-networks-and-deep-learning/di-wu-men-ke-xu-lie-mo-xing-sequence-models/di-wu-men-kexulie-mo-578b28-sequence-models/recurrent-neural-networks/15-bu-tong-lei-xing-dexun-huan-shen-jing-wang-luo-ff08-different-types-of-rnns.md).

# 1.5 不同类型的循环神经网络（Different types of RNNs）

RNN模型包含以下几个类型：

* **一对一，**&#x5F53;去掉$$a^{<0>}$$时它就是一种标准类型的神经网络
* **一对多**，比如音乐生成或者序列生成
* **多对一**，如是情感分类的例子，首先读取输入，一个电影评论的文本，然后判断他们是否喜欢电影还是不喜欢
* **多对多**，如命名实体识别，$$T\_{x}=T\_{y}$$
* **多对多，**&#x5982;机器翻译，$$T\_x\neq T\_y$$

[![](https://github.com/fengdu78/deeplearning_ai_books/raw/master/images/1daa38085604dd04e91ebc5e609d1179.png)](https://github.com/fengdu78/deeplearning_ai_books/blob/master/images/1daa38085604dd04e91ebc5e609d1179.png)