提交 b676e865 编写于 作者: R ranqiu

Merge branch 'develop' of https://github.com/PaddlePaddle/models into mt_with_external_memory

#!/bin/bash
#!/usr/bin/env bash
set -e
# clang-format hook without version check
readonly VERSION="3.9"
version=$(clang-format -version)
if ! [[ $version == *"$VERSION"* ]]; then
echo "clang-format version check failed."
echo "a version contains '$VERSION' is needed, but get '$version'"
echo "you can install the right version, and make an soft-link to '\$PATH' env"
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# models 简介
[![Documentation Status](https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat)](https://github.com/PaddlePaddle/models)
[![Documentation Status](https://img.shields.io/badge/中文文档-最新-brightgreen.svg)](https://github.com/PaddlePaddle/models)
[![License](https://img.shields.io/badge/license-Apache%202-blue.svg)](LICENSE)
PaddlePaddle提供了丰富的运算单元,帮助大家以模块化的方式构建起千变万化的深度学习模型来解决不同的应用问题。这里,我们针对常见的机器学习任务,提供了不同的神经网络模型供大家学习和使用。
## 1. 词向量
词向量用一个实向量表示词语,向量的每个维都表示文本的某种潜在语法或语义特征,是深度学习应用于自然语言处理领域最成功的概念和成果之一。广义的,词向量也可以应用于普通离散特征。词向量的学习通常都是一个无监督的学习过程,因此,可以充分利用海量的无标记数据以捕获特征之间的关系,也可以有效地解决特征稀疏、标签数据缺失、数据噪声等问题。然而,在常见词向量学习方法中,模型最后一层往往会遇到一个超大规模的分类问题,是计算性能的瓶颈。
在词向量的例子中,我们向大家展示如何使用Hierarchical-Sigmoid 和噪声对比估计(Noise Contrastive Estimation,NCE)来加速词向量的学习。
- 1.1 [Hsigmoid加速词向量训练](https://github.com/PaddlePaddle/models/tree/develop/hsigmoid)
- 1.2 [噪声对比估计加速词向量训练](https://github.com/PaddlePaddle/models/tree/develop/nce_cost)
## 2. 使用循环神经网络语言模型生成文本
语言模型是自然语言处理领域里一个重要的基础模型,除了得到词向量(语言模型训练的副产物),还可以帮助我们生成文本。给定若干个词,语言模型可以帮助我们预测下一个最可能出现的词。在利用语言模型生成文本的例子中,我们重点介绍循环神经网络语言模型,大家可以通过文档中的使用说明快速适配到自己的训练语料,完成自动写诗、自动写散文等有趣的模型。
- 2.1 [使用循环神经网络语言模型生成文本](https://github.com/PaddlePaddle/models/tree/develop/generate_sequence_by_rnn_lm)
## 3. 点击率预估
点击率预估模型预判用户对一条广告点击的概率,对每次广告的点击情况做出预测,是广告技术的核心算法之一。逻谛斯克回归对大规模稀疏特征有着很好的学习能力,在点击率预估任务发展的早期一统天下。近年来,DNN 模型由于其强大的学习能力逐渐接过点击率预估任务的大旗。
在点击率预估的例子中,我们给出谷歌提出的 Wide & Deep 模型。这一模型融合了适用于学习抽象特征的 DNN 和适用于大规模稀疏特征的逻谛斯克回归两者模型的优点,可以作为一种相对成熟的模型框架使用, 在工业界也有一定的应用。
- 3.1 [Wide & deep 点击率预估模型](https://github.com/PaddlePaddle/models/tree/develop/ctr)
## 4. 文本分类
文本分类是自然语言处理领域最基础的任务之一,深度学习方法能够免除复杂的特征工程,直接使用原始文本作为输入,数据驱动地最优化分类准确率。
在文本分类的例子中,我们以情感分类任务为例,提供了基于DNN的非序列文本分类模型,以及基于CNN的序列模型供大家学习和使用(基于LSTM的模型见PaddleBook中[情感分类](https://github.com/PaddlePaddle/book/blob/develop/06.understand_sentiment/README.cn.md)一课)。
- 4.1 [基于 DNN / CNN 的情感分类](https://github.com/PaddlePaddle/models/tree/develop/text_classification)
## 5. 排序学习
排序学习(Learning to Rank, LTR)是信息检索和搜索引擎研究的核心问题之一,通过机器学习方法学习一个分值函数对待排序的候选进行打分,再根据分值的高低确定序关系。深度神经网络可以用来建模分值函数,构成各类基于深度学习的LTR模型。
在排序学习的例子中,我们介绍基于 RankLoss 损失函数的 Pairwise 排序模型和基于LambdaRank损失函数的Listwise排序模型(Pointwise学习策略见PaddleBook中[推荐系统](https://github.com/PaddlePaddle/book/blob/develop/05.recommender_system/README.cn.md)一课)。
- 5.1 [基于 Pairwise 和 Listwise 的排序学习](https://github.com/PaddlePaddle/models/tree/develop/ltr)
## 6. 深度结构化语义模型
深度结构化语义模型使用DNN模型在一个连续的语义空间中学习文本低纬的向量表示,最终建模两个句子间的语义相似度。
本例中我们演示如何使用 PaddlePaddle实现一个通用的深度结构化语义模型来建模两个字符串间的语义相似度。
模型支持CNN(卷积网络)、FC(全连接网络)、RNN(递归神经网络)等不同的网络结构,以及分类、回归、排序等不同损失函数,采用了比较通用的数据格式,用户替换数据便可以在真实场景中使用。
- 6.1 [深度结构化语义模型](https://github.com/PaddlePaddle/models/tree/develop/dssm)
## 7. 序列标注
给定输入序列,序列标注模型为序列中每一个元素贴上一个类别标签,是自然语言处理领域最基础的任务之一。随着深度学习的不断探索和发展,利用循环神经网络学习输入序列的特征表示,条件随机场(Conditional Random Field, CRF)在特征基础上完成序列标注任务,逐渐成为解决序列标注问题的标配解决方案。
在序列标注的例子中,我们以命名实体识别(Named Entity Recognition,NER)任务为例,介绍如何训练一个端到端的序列标注模型。
- 7.1 [命名实体识别](https://github.com/PaddlePaddle/models/tree/develop/sequence_tagging_for_ner)
## 8. 序列到序列学习
序列到序列学习实现两个甚至是多个不定长模型之间的映射,有着广泛的应用,包括:机器翻译、智能对话与问答、广告创意语料生成、自动编码(如金融画像编码)、判断多个文本串之间的语义相关性等。
在序列到序列学习的例子中,我们以机器翻译任务为例,提供了多种改进模型,供大家学习和使用。包括:不带注意力机制的序列到序列映射模型,这一模型是所有序列到序列学习模型的基础;使用 scheduled sampling 改善 RNN 模型在生成任务中的错误累积问题;带外部记忆机制的神经机器翻译,通过增强神经网络的记忆能力,来完成复杂的序列到序列学习任务。
- 8.1 [无注意力机制的编码器解码器模型](https://github.com/PaddlePaddle/models/tree/develop/nmt_without_attention)
## 9. 图像分类
图像相比文字能够提供更加生动、容易理解及更具艺术感的信息,是人们转递与交换信息的重要来源。在图像分类的例子中,我们向大家介绍如何在PaddlePaddle中训练AlexNet、VGG、GoogLeNet和ResNet模型。同时还提供了一个模型转换工具,能够将Caffe训练好的模型文件,转换为PaddlePaddle的模型文件。
- 9.1 [将Caffe模型文件转换为PaddlePaddle模型文件](https://github.com/PaddlePaddle/models/tree/develop/image_classification/caffe2paddle)
- 9.2 [AlexNet](https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.3 [VGG](https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.4 [Residual Network](https://github.com/PaddlePaddle/models/tree/develop/image_classification)
## Copyright and License
PaddlePaddle is provided under the [Apache-2.0 license](LICENSE).
# models 简介
# Introduction to models
[![Documentation Status](https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat)](https://github.com/PaddlePaddle/models)
[![Documentation Status](https://img.shields.io/badge/中文文档-最新-brightgreen.svg)](https://github.com/PaddlePaddle/models)
[![License](https://img.shields.io/badge/license-Apache%202-blue.svg)](LICENSE)
PaddlePaddle provides a rich set of computational units to enable users to adopt a modular approach to solving various learning problems. In this repo, we demonstrate how to use PaddlePaddle to solve common machine learning tasks, providing several different neural network model that anyone can easily learn and use.
PaddlePaddle提供了丰富的运算单元,帮助大家以模块化的方式构建起千变万化的深度学习模型来解决不同的应用问题。这里,我们针对常见的机器学习任务,提供了不同的神经网络模型供大家学习和使用。
## 1. Word Embedding
The word embedding expresses words with a real vector. Each dimension of the vector represents some of the latent grammatical or semantic features of the text and is one of the most successful concepts in the field of natural language processing. The generalized word vector can also be applied to discrete features. The study of word vector is usually an unsupervised learning. Therefore, it is possible to take full advantage of massive unmarked data to capture the relationship between features and to solve the problem of sparse features, missing tag data, and data noise. However, in the common word vector learning method, the last layer of the model often encounters a large-scale classification problem, which is the bottleneck of computing performance.
## 1. 词向量
In the example of word vectors, we show how to use Hierarchical-Sigmoid and Noise Contrastive Estimation (NCE) to accelerate word-vector learning.
词向量用一个实向量表示词语,向量的每个维都表示文本的某种潜在语法或语义特征,是深度学习应用于自然语言处理领域最成功的概念和成果之一。广义的,词向量也可以应用于普通离散特征。词向量的学习通常都是一个无监督的学习过程,因此,可以充分利用海量的无标记数据以捕获特征之间的关系,也可以有效地解决特征稀疏、标签数据缺失、数据噪声等问题。然而,在常见词向量学习方法中,模型最后一层往往会遇到一个超大规模的分类问题,是计算性能的瓶颈。
- 1.1 [Hsigmoid Accelerated Word Vector Training] (https://github.com/PaddlePaddle/models/tree/develop/hsigmoid)
- 1.2 [Noise Contrast Estimation Accelerated Word Vector Training] (https://github.com/PaddlePaddle/models/tree/develop/nce_cost)
在词向量的例子中,我们向大家展示如何使用Hierarchical-Sigmoid 和噪声对比估计(Noise Contrastive Estimation,NCE)来加速词向量的学习。
- 1.1 [Hsigmoid加速词向量训练](https://github.com/PaddlePaddle/models/tree/develop/hsigmoid)
- 1.2 [噪声对比估计加速词向量训练](https://github.com/PaddlePaddle/models/tree/develop/nce_cost)
## 2. Generate text using the recurrent neural network language model
The language model is important in the field of natural language processing. In addition to getting the word vector (a by-product of language model training), it can also help us to generate text. Given a number of words, the language model can help us predict the next most likely word. In the example of using the language model to generate text, we focus on the recurrent neural network language model. We can use the instructions in the document quickly adapt to their training corpus, complete automatic writing poetry, automatic writing prose and other interesting models.
## 2. 使用循环神经网络语言模型生成文本
- 2.1 [Generate text using the annotated neural network language model] (https://github.com/PaddlePaddle/models/tree/develop/generate_sequence_by_rnn_lm)
语言模型是自然语言处理领域里一个重要的基础模型,除了得到词向量(语言模型训练的副产物),还可以帮助我们生成文本。给定若干个词,语言模型可以帮助我们预测下一个最可能出现的词。在利用语言模型生成文本的例子中,我们重点介绍循环神经网络语言模型,大家可以通过文档中的使用说明快速适配到自己的训练语料,完成自动写诗、自动写散文等有趣的模型。
## 3. Click-Through Rate prediction
The click-through rate model predicts the probability that a user will click on an ad. This is widely used for advertising technology. Logistic Regression has a good learning performance for large-scale sparse features in the early stages of the development of click-through rate prediction. In recent years, DNN model because of its strong learning ability to gradually take the banner rate of the task of the banner.
- 2.1 [使用循环神经网络语言模型生成文本](https://github.com/PaddlePaddle/models/tree/develop/generate_sequence_by_rnn_lm)
In the example of click-through rate estimates, we give the Google's Wide & Deep model. This model combines the advantages of DNN and the applicable logistic regression model for DNN and large-scale sparse features.
## 3. 点击率预估
- 3.1 [Click-Through Rate Model] (https://github.com/PaddlePaddle/models/tree/develop/ctr)
点击率预估模型预判用户对一条广告点击的概率,对每次广告的点击情况做出预测,是广告技术的核心算法之一。逻谛斯克回归对大规模稀疏特征有着很好的学习能力,在点击率预估任务发展的早期一统天下。近年来,DNN 模型由于其强大的学习能力逐渐接过点击率预估任务的大旗。
## 4. Text classification
在点击率预估的例子中,我们给出谷歌提出的 Wide & Deep 模型。这一模型融合了适用于学习抽象特征的 DNN 和适用于大规模稀疏特征的逻谛斯克回归两者模型的优点,可以作为一种相对成熟的模型框架使用, 在工业界也有一定的应用。
Text classification is one of the most basic tasks in natural language processing. The deep learning method can eliminate the complex feature engineering, and use the original text as input to optimize the classification accuracy.
- 3.1 [Wide & deep 点击率预估模型](https://github.com/PaddlePaddle/models/tree/develop/ctr)
For text classification, we provide a non-sequential text classification model based on DNN and CNN. (For LSTM-based model, please refer to PaddleBook [Sentiment Analysis] https://github.com/PaddlePaddle/book/blob/develop/06.understand_sentiment/README.cn.md)).
## 4. 文本分类
- 4.1 [Sentiment analysis based on DNN / CNN] (https://github.com/PaddlePaddle/models/tree/develop/text_classification)
文本分类是自然语言处理领域最基础的任务之一,深度学习方法能够免除复杂的特征工程,直接使用原始文本作为输入,数据驱动地最优化分类准确率。
## 5. Learning to rank
在文本分类的例子中,我们以情感分类任务为例,提供了基于DNN的非序列文本分类模型,以及基于CNN的序列模型供大家学习和使用(基于LSTM的模型见PaddleBook中[情感分类](https://github.com/PaddlePaddle/book/blob/develop/06.understand_sentiment/README.cn.md)一课)。
Learning to rank (LTR) is one of the core problems in information retrieval and search engine research. Training data is used by a learning algorithm to produce a ranking model which computes the relevance of documents for actual queries.
The depth neural network can be used to model the fractional function to form various LTR models based on depth learning.
- 4.1 [基于 DNN / CNN 的情感分类](https://github.com/PaddlePaddle/models/tree/develop/text_classification)
The algorithms for learning to rank are usually categorized into three groups by their input representation and the loss function. These are pointwise, pairwise and listwise approaches. Here we demonstrate RankLoss loss function method (pairwise approach), and LambdaRank loss function method (listwise approach). (For Pointwise approaches, please refer to [Recommended System] (https://github.com/PaddlePaddle/book/ blob / develop / 05.recommender_system / README.cn.md)).
## 5. 排序学习
- 5.1 [Learning to rank based on Pairwise and Listwise approches] (https://github.com/PaddlePaddle/models/tree/develop/ltr)
排序学习(Learning to Rank, LTR)是信息检索和搜索引擎研究的核心问题之一,通过机器学习方法学习一个分值函数对待排序的候选进行打分,再根据分值的高低确定序关系。深度神经网络可以用来建模分值函数,构成各类基于深度学习的LTR模型。
## 6. Semantic model
The deep structured semantic model uses the DNN model to learn the vector representation of the low latitude in a continuous semantic space, finally models the semantic similarity between the two sentences.
在排序学习的例子中,我们介绍基于 RankLoss 损失函数的 Pairwise 排序模型和基于LambdaRank损失函数的Listwise排序模型(Pointwise学习策略见PaddleBook中[推荐系统](https://github.com/PaddlePaddle/book/blob/develop/05.recommender_system/README.cn.md)一课)。
In this example, we demonstrate how to use PaddlePaddle to implement a generic deep structured semantic model to model the semantic similarity between two strings. The model supports different network structures such as CNN (Convolutional Network), FC (Fully Connected Network), RNN (Recurrent Neural Network), and different loss functions such as classification, regression, and sequencing.
- 5.1 [基于 Pairwise 和 Listwise 的排序学习](https://github.com/PaddlePaddle/models/tree/develop/ltr)
- 6.1 [Deep structured semantic model] (https://github.com/PaddlePaddle/models/tree/develop/dssm)
## 6. 深度结构化语义模型
深度结构化语义模型使用DNN模型在一个连续的语义空间中学习文本低纬的向量表示,最终建模两个句子间的语义相似度。
## 7. Sequence tagging
本例中我们演示如何使用 PaddlePaddle实现一个通用的深度结构化语义模型来建模两个字符串间的语义相似度。
模型支持CNN(卷积网络)、FC(全连接网络)、RNN(递归神经网络)等不同的网络结构,以及分类、回归、排序等不同损失函数,采用了比较通用的数据格式,用户替换数据便可以在真实场景中使用。
Given the input sequence, the sequence tagging model is one of the most basic tasks in the natural language processing by assigning a category tag to each element in the sequence. Recurrent neural network models with Conditional Random Field (CRF) are commonly used for sequence tagging tasks.
- 6.1 [深度结构化语义模型](https://github.com/PaddlePaddle/models/tree/develop/dssm)
In the example of the sequence tagging, we describe how to train an end-to-end sequence tagging model with the Named Entity Recognition (NER) task as an example.
## 7. 序列标注
- 7.1 [Name Entity Recognition] (https://github.com/PaddlePaddle/models/tree/develop/sequence_tagging_for_ner)
给定输入序列,序列标注模型为序列中每一个元素贴上一个类别标签,是自然语言处理领域最基础的任务之一。随着深度学习的不断探索和发展,利用循环神经网络学习输入序列的特征表示,条件随机场(Conditional Random Field, CRF)在特征基础上完成序列标注任务,逐渐成为解决序列标注问题的标配解决方案。
## 8. Sequence to sequence learning
在序列标注的例子中,我们以命名实体识别(Named Entity Recognition,NER)任务为例,介绍如何训练一个端到端的序列标注模型。
Sequence-to-sequence model has a wide range of applications. This includes machine translation, dialogue system, and parse tree generation.
- 7.1 [命名实体识别](https://github.com/PaddlePaddle/models/tree/develop/sequence_tagging_for_ner)
As an example for sequence-to-sequence learning, we take the machine translation task. We demonstrate the sequence-to-sequence mapping model without attention mechanism, which is the basis for all sequence-to-sequence learning models. We will use scheduled sampling to improve the problem of error accumulation in the RNN model, and machine translation with external memory mechanism.
## 8. 序列到序列学习
- 8.1 [Basic Sequence-to-sequence model] (https://github.com/PaddlePaddle/models/tree/develop/nmt_without_attention)
序列到序列学习实现两个甚至是多个不定长模型之间的映射,有着广泛的应用,包括:机器翻译、智能对话与问答、广告创意语料生成、自动编码(如金融画像编码)、判断多个文本串之间的语义相关性等。
## 9. Image classification
在序列到序列学习的例子中,我们以机器翻译任务为例,提供了多种改进模型,供大家学习和使用。包括:不带注意力机制的序列到序列映射模型,这一模型是所有序列到序列学习模型的基础;使用 scheduled sampling 改善 RNN 模型在生成任务中的错误累积问题;带外部记忆机制的神经机器翻译,通过增强神经网络的记忆能力,来完成复杂的序列到序列学习任务。
For the example of image classification, we show you how to train AlexNet, VGG, GoogLeNet and ResNet models in PaddlePaddle. It also provides a model conversion tool that converts Caffe trained model files into PaddlePaddle model files.
- 8.1 [无注意力机制的编码器解码器模型](https://github.com/PaddlePaddle/models/tree/develop/nmt_without_attention)
## 9. 图像分类
图像相比文字能够提供更加生动、容易理解及更具艺术感的信息,是人们转递与交换信息的重要来源。在图像分类的例子中,我们向大家介绍如何在PaddlePaddle中训练AlexNet、VGG、GoogLeNet和ResNet模型。同时还提供了一个模型转换工具,能够将Caffe训练好的模型文件,转换为PaddlePaddle的模型文件。
- 9.1 [将Caffe模型文件转换为PaddlePaddle模型文件](https://github.com/PaddlePaddle/models/tree/develop/image_classification/caffe2paddle)
- 9.2 [AlexNet](https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.3 [VGG](https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.4 [Residual Network](https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.1 [convert Caffe model file to PaddlePaddle model file] (https://github.com/PaddlePaddle/models/tree/develop/image_classification/caffe2paddle)
- 9.2 [AlexNet] (https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.3 [VGG] (https://github.com/PaddlePaddle/models/tree/develop/image_classification)
- 9.4 [Residual Network] (https://github.com/PaddlePaddle/models/tree/develop/image_classification)
## Copyright and License
PaddlePaddle is provided under the [Apache-2.0 license](LICENSE).
PaddlePaddle is provided under the [Apache-2.0 license] (LICENSE).
# 点击率预估
# Click-Through Rate Prediction
以下是本例目录包含的文件以及对应说明:
## Introduction
```
├── README.md # 本教程markdown 文档
├── dataset.md # 数据集处理教程
├── images # 本教程图片目录
│   ├── lr_vs_dnn.jpg
│   └── wide_deep.png
├── infer.py # 预测脚本
├── network_conf.py # 模型网络配置
├── reader.py # data reader
├── train.py # 训练脚本
└── utils.py # helper functions
└── avazu_data_processer.py # 示例数据预处理脚本
```
## 背景介绍
CTR(Click-Through Rate,点击率预估)\[[1](https://en.wikipedia.org/wiki/Click-through_rate)\]
是对用户点击一个特定链接的概率做出预测,是广告投放过程中的一个重要环节。精准的点击率预估对在线广告系统收益最大化具有重要意义。
CTR(Click-Through Rate)\[[1](https://en.wikipedia.org/wiki/Click-through_rate)\]
is a prediction of the probability that a user clicks on an advertisement. This model is widely used in the advertisement industry. Accurate click rate estimates are important for maximizing online advertising revenue.
当有多个广告位时,CTR 预估一般会作为排序的基准,比如在搜索引擎的广告系统里,当用户输入一个带商业价值的搜索词(query)时,系统大体上会执行下列步骤来展示广告:
When there are multiple ad slots, CTR estimates are generally used as a baseline for ranking. For example, in a search engine's ad system, when the user enters a query, the system typically performs the following steps to show relevant ads.
1. 获取与用户搜索词相关的广告集合
2. 业务规则和相关性过滤
3. 根据拍卖机制和 CTR 排序
4. 展出广告
1. Get the ad collection associated with the user's search term.
2. Business rules and relevance filtering.
3. Rank by auction mechanism and CTR.
4. Show ads.
可以看到,CTR 在最终排序中起到了很重要的作用。
Here,CTR plays a crucial role.
### 发展阶段
在业内,CTR 模型经历了如下的发展阶段:
### Brief history
Historically, the CTR prediction model has been evolving as follows.
- Logistic Regression(LR) / GBDT + 特征工程
- LR + DNN 特征
- DNN + 特征工程
- Logistic Regression(LR) / Gradient Boosting Decision Trees (GBDT) + feature engineering
- LR + Deep Neural Network (DNN)
- DNN + feature engineering
在发展早期时 LR 一统天下,但最近 DNN 模型由于其强大的学习能力和逐渐成熟的性能优化,
逐渐地接过 CTR 预估任务的大旗。
In the early stages of development LR dominated, but the recent years DNN based models are mainly used.
### LR vs DNN
下图展示了 LR 和一个 \(3x2\) 的 DNN 模型的结构:
The following figure shows the structure of LR and DNN model:
<p align="center">
<img src="images/lr_vs_dnn.jpg" width="620" hspace='10'/> <br/>
Figure 1. LR 和 DNN 模型结构对比
Figure 1. LR and DNN model structure comparison
</p>
LR 的蓝色箭头部分可以直接类比到 DNN 中对应的结构,可以看到 LR 和 DNN 有一些共通之处(比如权重累加),
但前者的模型复杂度在相同输入维度下比后者可能低很多(从某方面讲,模型越复杂,越有潜力学习到更复杂的信息);
如果 LR 要达到匹敌 DNN 的学习能力,必须增加输入的维度,也就是增加特征的数量,
这也就是为何 LR 和大规模的特征工程必须绑定在一起的原因。
We can see, LR and CNN have some common structures. However, DNN can have non-linear relation between input and output values by adding activation unit and further layers. This enables DNN to achieve better learning results in CTR estimates.
LR 对于 DNN 模型的优势是对大规模稀疏特征的容纳能力,包括内存和计算量等方面,工业界都有非常成熟的优化方法;
而 DNN 模型具有自己学习新特征的能力,一定程度上能够提升特征使用的效率,
这使得 DNN 模型在同样规模特征的情况下,更有可能达到更好的学习效果。
In the following, we demonstrate how to use PaddlePaddle to learn to predict CTR.
本文后面的章节会演示如何使用 PaddlePaddle 编写一个结合两者优点的模型。
## Data and Model formation
Here `click` is the learning objective. There are several ways to learn the objectives.
## 数据和任务抽象
1. Direct learning click, 0,1 for binary classification
2. Learning to rank, pairwise rank or listwise rank
3. Measure the ad click rate of each ad, then rank by the click rate.
我们可以将 `click` 作为学习目标,任务可以有以下几种方案:
In this example, we use the first method.
1. 直接学习 click,0,1 作二元分类
2. Learning to rank, 具体用 pairwise rank(标签 1>0)或者 listwise rank
3. 统计每个广告的点击率,将同一个 query 下的广告两两组合,点击率高的>点击率低的,做 rank 或者分类
We use the Kaggle `Click-through rate prediction` task \[[2](https://www.kaggle.com/c/avazu-ctr-prediction/data)\].
我们直接使用第一种方法做分类任务。
Please see the [data process](./dataset.md) for pre-processing data.
我们使用 Kaggle 上 `Click-through rate prediction` 任务的数据集\[[2](https://www.kaggle.com/c/avazu-ctr-prediction/data)\] 来演示本例中的模型。
具体的特征处理方法参看 [data process](./dataset.md)
本教程中演示模型的输入格式如下:
The input data format for the demo model in this tutorial is as follows:
```
# <dnn input ids> \t <lr input sparse values> \t click
......@@ -84,10 +59,10 @@ LR 对于 DNN 模型的优势是对大规模稀疏特征的容纳能力,包括
23 231 \t 1230:0.12 13421:0.9 \t 1
```
详细的格式描述如下
Description
- `dnn input ids` 采用 one-hot 表示,只需要填写值为1的ID(注意这里不是变长输入)
- `lr input sparse values` 使用了 `ID:VALUE` 的表示,值部分最好规约到值域 `[-1, 1]`
- `dnn input ids` one-hot coding.
- `lr input sparse values` Use `ID:VALUE` , values are preferaly scaled to the range `[-1, 1]`
此外,模型训练时需要传入一个文件描述 dnn 和 lr两个子模型的输入维度,文件的格式如下:
......@@ -96,9 +71,9 @@ dnn_input_dim: <int>
lr_input_dim: <int>
```
其中, `<int>` 表示一个整型数值。
<int> represents an integer value.
本目录下的 `avazu_data_processor.py` 可以对下载的演示数据集\[[2](#参考文档)\] 进行处理,具体使用方法参考如下说明:
`avazu_data_processor.py` can be used to download the data set \[[2](#参考文档)\]and pre-process the data.
```
usage: avazu_data_processer.py [-h] --data_path DATA_PATH --output_dir
......@@ -123,40 +98,38 @@ optional arguments:
size of the trainset (default: 100000)
```
- `data_path` 是待处理的数据路径
- `output_dir` 生成数据的输出路径
- `num_lines_to_detect` 预先扫描数据生成ID的个数,这里是扫描的文件行数
- `test_set_size` 生成测试集的行数
- `train_size` 生成训练姐的行数
- `data_path` The data path to be processed
- `output_dir` The output path of the data
- `num_lines_to_detect` The number of generated IDs
- `test_set_size` The number of rows for the test set
- `train_size` The number of rows of training set
## Wide & Deep Learning Model
谷歌在 16 年提出了 Wide & Deep Learning 的模型框架,用于融合适合学习抽象特征的 DNN 和 适用于大规模稀疏特征的 LR 两种模型的优点。
Google proposed a model framework for Wide & Deep Learning to integrate the advantages of both DNNs suitable for learning abstract features and LR models for large sparse features.
### 模型简介
### Introduction to the model
Wide & Deep Learning Model\[[3](#参考文献)\] 可以作为一种相对成熟的模型框架使用,
在 CTR 预估的任务中工业界也有一定的应用,因此本文将演示使用此模型来完成 CTR 预估的任务。
Wide & Deep Learning Model\[[3](#References)\] is a relatively mature model, but this model is still being used in the CTR predicting task. Here we demonstrate the use of this model to complete the CTR predicting task.
模型结构如下:
The model structure is as follows:
<p align="center">
<img src="images/wide_deep.png" width="820" hspace='10'/> <br/>
Figure 2. Wide & Deep Model
</p>
模型左边的 Wide 部分,可以容纳大规模系数特征,并且对一些特定的信息(比如 ID)有一定的记忆能力;
而模型右边的 Deep 部分,能够学习特征间的隐含关系,在相同数量的特征下有更好的学习和推导能力。
The wide part of the left side of the model can accommodate large-scale coefficient features and has some memory for some specific information (such as ID); and the Deep part of the right side of the model can learn the implicit relationship between features.
### 编写模型输入
### Model Input
模型只接受 3 个输入,分别是
The model has three inputs as follows.
- `dnn_input`也就是 Deep 部分的输入
- `lr_input`也就是 Wide 部分的输入
- `click`点击与否,作为二分类模型学习的标签
- `dnn_input`the Deep part of the input
- `lr_input`the wide part of the input
- `click`click on or not
```python
dnn_merged_input = layer.data(
......@@ -170,9 +143,9 @@ lr_merged_input = layer.data(
click = paddle.layer.data(name='click', type=dtype.dense_vector(1))
```
### 编写 Wide 部分
### Wide part
Wide 部分直接使用了 LR 模型,但激活函数改成了 `RELU` 来加速
Wide part uses of the LR model, but the activation function changed to `RELU` for speed.
```python
def build_lr_submodel():
......@@ -181,9 +154,9 @@ def build_lr_submodel():
return fc
```
### 编写 Deep 部分
### Deep part
Deep 部分使用了标准的多层前向传导的 DNN 模型
The Deep part uses a standard multi-layer DNN.
```python
def build_dnn_submodel(dnn_layer_dims):
......@@ -199,10 +172,9 @@ def build_dnn_submodel(dnn_layer_dims):
return _input_layer
```
### 两者融合
### Combine
两个 submodel 的最上层输出加权求和得到整个模型的输出,输出部分使用 `sigmoid` 作为激活函数,得到区间 (0,1) 的预测值,
来逼近训练数据中二元类别的分布,并最终作为 CTR 预估的值使用。
The output section uses `sigmoid` function to output (0,1) as the prediction value.
```python
# conbine DNN and LR submodels
......@@ -217,7 +189,7 @@ def combine_submodels(dnn, lr):
return fc
```
### 训练任务的定义
### Training
```python
dnn = build_dnn_submodel(dnn_layer_dims)
lr = build_lr_submodel()
......@@ -263,16 +235,17 @@ trainer.train(
event_handler=event_handler,
num_passes=100)
```
## 运行训练和测试
训练模型需要如下步骤:
1. 准备训练数据
1.[Kaggle CTR](https://www.kaggle.com/c/avazu-ctr-prediction/data) 下载 train.gz
2. 解压 train.gz 得到 train.txt
## Run training and testing
The model go through the following steps:
1. Prepare training data
1. Download train.gz from [Kaggle CTR](https://www.kaggle.com/c/avazu-ctr-prediction/data) .
2. Unzip train.gz to get train.txt
3. `mkdir -p output; python avazu_data_processer.py --data_path train.txt --output_dir output --num_lines_to_detect 1000 --test_set_size 100` 生成演示数据
2. 执行 `python train.py --train_data_path ./output/train.txt --test_data_path ./output/test.txt --data_meta_file ./output/data.meta.txt --model_type=0` 开始训练
2. Execute `python train.py --train_data_path ./output/train.txt --test_data_path ./output/test.txt --data_meta_file ./output/data.meta.txt --model_type=0`. Start training.
上面第2个步骤可以为 `train.py` 填充命令行参数来定制模型的训练过程,具体的命令行参数及用法如下
The argument options for `train.py` are as follows.
```
usage: train.py [-h] --train_data_path TRAIN_DATA_PATH
......@@ -303,15 +276,16 @@ optional arguments:
classification)
```
- `train_data_path` : 训练集的路径
- `test_data_path` : 测试集的路径
- `num_passes`: 模型训练多少轮
- `data_meta_file`: 参考[数据和任务抽象](### 数据和任务抽象)的描述。
- `model_type`: 模型分类或回归
- `train_data_path` : The path of the training set
- `test_data_path` : The path of the testing set
- `num_passes`: number of rounds of model training
- `data_meta_file`: Please refer to [数据和任务抽象](### 数据和任务抽象)的描述。
- `model_type`: Model classification or regressio
## Use the training model for prediction
The training model can be used to predict new data, and the format of the forecast data is as follows.
## 用训好的模型做预测
训好的模型可以用来预测新的数据, 预测数据的格式为
```
# <dnn input ids> \t <lr input sparse values>
......@@ -319,9 +293,9 @@ optional arguments:
23 231 \t 1230:0.12 13421:0.9
```
这里与训练数据的格式唯一不同的地方,就是没有标签,也就是训练数据中第3列 `click` 对应的数值。
Here the only difference to the training data is that there is no label (i.e. `click` values).
`infer.py` 的使用方法如下
We now can use `infer.py` to perform inference.
```
usage: infer.py [-h] --model_gz_path MODEL_GZ_PATH --data_path DATA_PATH
......@@ -345,21 +319,21 @@ optional arguments:
classification)
```
- `model_gz_path_model``gz` 压缩过的模型路径
- `data_path` 需要预测的数据路径
- `prediction_output_paht`:预测输出的路径
- `data_meta_file`参考[数据和任务抽象](### 数据和任务抽象)的描述
- `model_type`分类或回归
- `model_gz_path_model`path for `gz` compressed data.
- `data_path`
- `prediction_output_patj`:path for the predicted values s
- `data_meta_file`Please refer to [数据和任务抽象](### 数据和任务抽象)
- `model_type`Classification or regression
示例数据可以用如下命令预测
The sample data can be predicted with the following command
```
python infer.py --model_gz_path <model_path> --data_path output/infer.txt --prediction_output_path predictions.txt --data_meta_path data.meta.txt
```
最终的预测结果位于 `predictions.txt`
The final prediction is written in `predictions.txt`
## 参考文献
## References
1. <https://en.wikipedia.org/wiki/Click-through_rate>
2. <https://www.kaggle.com/c/avazu-ctr-prediction/data>
3. Cheng H T, Koc L, Harmsen J, et al. [Wide & deep learning for recommender systems](https://arxiv.org/pdf/1606.07792.pdf)[C]//Proceedings of the 1st Workshop on Deep Learning for Recommender Systems. ACM, 2016: 7-10.
......@@ -40,85 +40,60 @@
<!-- This block will be replaced by each markdown file content. Please do not change lines below.-->
<div id="markdown" style='display:none'>
# 点击率预估
# Click-Through Rate Prediction
以下是本例目录包含的文件以及对应说明:
## Introduction
```
├── README.md # 本教程markdown 文档
├── dataset.md # 数据集处理教程
├── images # 本教程图片目录
│   ├── lr_vs_dnn.jpg
│   └── wide_deep.png
├── infer.py # 预测脚本
├── network_conf.py # 模型网络配置
├── reader.py # data reader
├── train.py # 训练脚本
└── utils.py # helper functions
└── avazu_data_processer.py # 示例数据预处理脚本
```
## 背景介绍
CTR(Click-Through Rate,点击率预估)\[[1](https://en.wikipedia.org/wiki/Click-through_rate)\]
是对用户点击一个特定链接的概率做出预测,是广告投放过程中的一个重要环节。精准的点击率预估对在线广告系统收益最大化具有重要意义。
CTR(Click-Through Rate)\[[1](https://en.wikipedia.org/wiki/Click-through_rate)\]
is a prediction of the probability that a user clicks on an advertisement. This model is widely used in the advertisement industry. Accurate click rate estimates are important for maximizing online advertising revenue.
当有多个广告位时,CTR 预估一般会作为排序的基准,比如在搜索引擎的广告系统里,当用户输入一个带商业价值的搜索词(query)时,系统大体上会执行下列步骤来展示广告:
When there are multiple ad slots, CTR estimates are generally used as a baseline for ranking. For example, in a search engine's ad system, when the user enters a query, the system typically performs the following steps to show relevant ads.
1. 获取与用户搜索词相关的广告集合
2. 业务规则和相关性过滤
3. 根据拍卖机制和 CTR 排序
4. 展出广告
1. Get the ad collection associated with the user's search term.
2. Business rules and relevance filtering.
3. Rank by auction mechanism and CTR.
4. Show ads.
可以看到,CTR 在最终排序中起到了很重要的作用。
Here,CTR plays a crucial role.
### 发展阶段
在业内,CTR 模型经历了如下的发展阶段:
### Brief history
Historically, the CTR prediction model has been evolving as follows.
- Logistic Regression(LR) / GBDT + 特征工程
- LR + DNN 特征
- DNN + 特征工程
- Logistic Regression(LR) / Gradient Boosting Decision Trees (GBDT) + feature engineering
- LR + Deep Neural Network (DNN)
- DNN + feature engineering
在发展早期时 LR 一统天下,但最近 DNN 模型由于其强大的学习能力和逐渐成熟的性能优化,
逐渐地接过 CTR 预估任务的大旗。
In the early stages of development LR dominated, but the recent years DNN based models are mainly used.
### LR vs DNN
下图展示了 LR 和一个 \(3x2\) 的 DNN 模型的结构:
The following figure shows the structure of LR and DNN model:
<p align="center">
<img src="images/lr_vs_dnn.jpg" width="620" hspace='10'/> <br/>
Figure 1. LR 和 DNN 模型结构对比
Figure 1. LR and DNN model structure comparison
</p>
LR 的蓝色箭头部分可以直接类比到 DNN 中对应的结构,可以看到 LR 和 DNN 有一些共通之处(比如权重累加),
但前者的模型复杂度在相同输入维度下比后者可能低很多(从某方面讲,模型越复杂,越有潜力学习到更复杂的信息);
如果 LR 要达到匹敌 DNN 的学习能力,必须增加输入的维度,也就是增加特征的数量,
这也就是为何 LR 和大规模的特征工程必须绑定在一起的原因。
We can see, LR and CNN have some common structures. However, DNN can have non-linear relation between input and output values by adding activation unit and further layers. This enables DNN to achieve better learning results in CTR estimates.
LR 对于 DNN 模型的优势是对大规模稀疏特征的容纳能力,包括内存和计算量等方面,工业界都有非常成熟的优化方法;
而 DNN 模型具有自己学习新特征的能力,一定程度上能够提升特征使用的效率,
这使得 DNN 模型在同样规模特征的情况下,更有可能达到更好的学习效果。
In the following, we demonstrate how to use PaddlePaddle to learn to predict CTR.
本文后面的章节会演示如何使用 PaddlePaddle 编写一个结合两者优点的模型。
## Data and Model formation
Here `click` is the learning objective. There are several ways to learn the objectives.
## 数据和任务抽象
1. Direct learning click, 0,1 for binary classification
2. Learning to rank, pairwise rank or listwise rank
3. Measure the ad click rate of each ad, then rank by the click rate.
我们可以将 `click` 作为学习目标,任务可以有以下几种方案:
In this example, we use the first method.
1. 直接学习 click,0,1 作二元分类
2. Learning to rank, 具体用 pairwise rank(标签 1>0)或者 listwise rank
3. 统计每个广告的点击率,将同一个 query 下的广告两两组合,点击率高的>点击率低的,做 rank 或者分类
We use the Kaggle `Click-through rate prediction` task \[[2](https://www.kaggle.com/c/avazu-ctr-prediction/data)\].
我们直接使用第一种方法做分类任务。
Please see the [data process](./dataset.md) for pre-processing data.
我们使用 Kaggle 上 `Click-through rate prediction` 任务的数据集\[[2](https://www.kaggle.com/c/avazu-ctr-prediction/data)\] 来演示本例中的模型。
具体的特征处理方法参看 [data process](./dataset.md)。
本教程中演示模型的输入格式如下:
The input data format for the demo model in this tutorial is as follows:
```
# <dnn input ids> \t <lr input sparse values> \t click
......@@ -126,10 +101,10 @@ LR 对于 DNN 模型的优势是对大规模稀疏特征的容纳能力,包括
23 231 \t 1230:0.12 13421:0.9 \t 1
```
详细的格式描述如下
Description
- `dnn input ids` 采用 one-hot 表示,只需要填写值为1的ID(注意这里不是变长输入)
- `lr input sparse values` 使用了 `ID:VALUE` 的表示,值部分最好规约到值域 `[-1, 1]`。
- `dnn input ids` one-hot coding.
- `lr input sparse values` Use `ID:VALUE` , values are preferaly scaled to the range `[-1, 1]`。
此外,模型训练时需要传入一个文件描述 dnn 和 lr两个子模型的输入维度,文件的格式如下:
......@@ -138,9 +113,9 @@ dnn_input_dim: <int>
lr_input_dim: <int>
```
其中, `<int>` 表示一个整型数值。
<int> represents an integer value.
本目录下的 `avazu_data_processor.py` 可以对下载的演示数据集\[[2](#参考文档)\] 进行处理,具体使用方法参考如下说明:
`avazu_data_processor.py` can be used to download the data set \[[2](#参考文档)\]and pre-process the data.
```
usage: avazu_data_processer.py [-h] --data_path DATA_PATH --output_dir
......@@ -165,40 +140,38 @@ optional arguments:
size of the trainset (default: 100000)
```
- `data_path` 是待处理的数据路径
- `output_dir` 生成数据的输出路径
- `num_lines_to_detect` 预先扫描数据生成ID的个数,这里是扫描的文件行数
- `test_set_size` 生成测试集的行数
- `train_size` 生成训练姐的行数
- `data_path` The data path to be processed
- `output_dir` The output path of the data
- `num_lines_to_detect` The number of generated IDs
- `test_set_size` The number of rows for the test set
- `train_size` The number of rows of training set
## Wide & Deep Learning Model
谷歌在 16 年提出了 Wide & Deep Learning 的模型框架,用于融合适合学习抽象特征的 DNN 和 适用于大规模稀疏特征的 LR 两种模型的优点。
Google proposed a model framework for Wide & Deep Learning to integrate the advantages of both DNNs suitable for learning abstract features and LR models for large sparse features.
### 模型简介
### Introduction to the model
Wide & Deep Learning Model\[[3](#参考文献)\] 可以作为一种相对成熟的模型框架使用,
在 CTR 预估的任务中工业界也有一定的应用,因此本文将演示使用此模型来完成 CTR 预估的任务。
Wide & Deep Learning Model\[[3](#References)\] is a relatively mature model, but this model is still being used in the CTR predicting task. Here we demonstrate the use of this model to complete the CTR predicting task.
模型结构如下:
The model structure is as follows:
<p align="center">
<img src="images/wide_deep.png" width="820" hspace='10'/> <br/>
Figure 2. Wide & Deep Model
</p>
模型左边的 Wide 部分,可以容纳大规模系数特征,并且对一些特定的信息(比如 ID)有一定的记忆能力;
而模型右边的 Deep 部分,能够学习特征间的隐含关系,在相同数量的特征下有更好的学习和推导能力。
The wide part of the left side of the model can accommodate large-scale coefficient features and has some memory for some specific information (such as ID); and the Deep part of the right side of the model can learn the implicit relationship between features.
### 编写模型输入
### Model Input
模型只接受 3 个输入,分别是
The model has three inputs as follows.
- `dnn_input` ,也就是 Deep 部分的输入
- `lr_input` ,也就是 Wide 部分的输入
- `click` , 点击与否,作为二分类模型学习的标签
- `dnn_input` ,the Deep part of the input
- `lr_input` ,the wide part of the input
- `click` , click on or not
```python
dnn_merged_input = layer.data(
......@@ -212,9 +185,9 @@ lr_merged_input = layer.data(
click = paddle.layer.data(name='click', type=dtype.dense_vector(1))
```
### 编写 Wide 部分
### Wide part
Wide 部分直接使用了 LR 模型,但激活函数改成了 `RELU` 来加速
Wide part uses of the LR model, but the activation function changed to `RELU` for speed.
```python
def build_lr_submodel():
......@@ -223,9 +196,9 @@ def build_lr_submodel():
return fc
```
### 编写 Deep 部分
### Deep part
Deep 部分使用了标准的多层前向传导的 DNN 模型
The Deep part uses a standard multi-layer DNN.
```python
def build_dnn_submodel(dnn_layer_dims):
......@@ -241,10 +214,9 @@ def build_dnn_submodel(dnn_layer_dims):
return _input_layer
```
### 两者融合
### Combine
两个 submodel 的最上层输出加权求和得到整个模型的输出,输出部分使用 `sigmoid` 作为激活函数,得到区间 (0,1) 的预测值,
来逼近训练数据中二元类别的分布,并最终作为 CTR 预估的值使用。
The output section uses `sigmoid` function to output (0,1) as the prediction value.
```python
# conbine DNN and LR submodels
......@@ -259,7 +231,7 @@ def combine_submodels(dnn, lr):
return fc
```
### 训练任务的定义
### Training
```python
dnn = build_dnn_submodel(dnn_layer_dims)
lr = build_lr_submodel()
......@@ -305,16 +277,17 @@ trainer.train(
event_handler=event_handler,
num_passes=100)
```
## 运行训练和测试
训练模型需要如下步骤:
1. 准备训练数据
1. 从 [Kaggle CTR](https://www.kaggle.com/c/avazu-ctr-prediction/data) 下载 train.gz
2. 解压 train.gz 得到 train.txt
## Run training and testing
The model go through the following steps:
1. Prepare training data
1. Download train.gz from [Kaggle CTR](https://www.kaggle.com/c/avazu-ctr-prediction/data) .
2. Unzip train.gz to get train.txt
3. `mkdir -p output; python avazu_data_processer.py --data_path train.txt --output_dir output --num_lines_to_detect 1000 --test_set_size 100` 生成演示数据
2. 执行 `python train.py --train_data_path ./output/train.txt --test_data_path ./output/test.txt --data_meta_file ./output/data.meta.txt --model_type=0` 开始训练
2. Execute `python train.py --train_data_path ./output/train.txt --test_data_path ./output/test.txt --data_meta_file ./output/data.meta.txt --model_type=0`. Start training.
上面第2个步骤可以为 `train.py` 填充命令行参数来定制模型的训练过程,具体的命令行参数及用法如下
The argument options for `train.py` are as follows.
```
usage: train.py [-h] --train_data_path TRAIN_DATA_PATH
......@@ -345,15 +318,16 @@ optional arguments:
classification)
```
- `train_data_path` : 训练集的路径
- `test_data_path` : 测试集的路径
- `num_passes`: 模型训练多少轮
- `data_meta_file`: 参考[数据和任务抽象](### 数据和任务抽象)的描述。
- `model_type`: 模型分类或回归
- `train_data_path` : The path of the training set
- `test_data_path` : The path of the testing set
- `num_passes`: number of rounds of model training
- `data_meta_file`: Please refer to [数据和任务抽象](### 数据和任务抽象)的描述。
- `model_type`: Model classification or regressio
## Use the training model for prediction
The training model can be used to predict new data, and the format of the forecast data is as follows.
## 用训好的模型做预测
训好的模型可以用来预测新的数据, 预测数据的格式为
```
# <dnn input ids> \t <lr input sparse values>
......@@ -361,9 +335,9 @@ optional arguments:
23 231 \t 1230:0.12 13421:0.9
```
这里与训练数据的格式唯一不同的地方,就是没有标签,也就是训练数据中第3列 `click` 对应的数值。
Here the only difference to the training data is that there is no label (i.e. `click` values).
`infer.py` 的使用方法如下
We now can use `infer.py` to perform inference.
```
usage: infer.py [-h] --model_gz_path MODEL_GZ_PATH --data_path DATA_PATH
......@@ -387,21 +361,21 @@ optional arguments:
classification)
```
- `model_gz_path_model`:用 `gz` 压缩过的模型路径
- `data_path` : 需要预测的数据路径
- `prediction_output_paht`:预测输出的路径
- `data_meta_file` :参考[数据和任务抽象](### 数据和任务抽象)的描述
- `model_type` :分类或回归
- `model_gz_path_model`:path for `gz` compressed data.
- `data_path` :
- `prediction_output_patj`:path for the predicted values s
- `data_meta_file` :Please refer to [数据和任务抽象](### 数据和任务抽象)
- `model_type` :Classification or regression
示例数据可以用如下命令预测
The sample data can be predicted with the following command
```
python infer.py --model_gz_path <model_path> --data_path output/infer.txt --prediction_output_path predictions.txt --data_meta_path data.meta.txt
```
最终的预测结果位于 `predictions.txt`。
The final prediction is written in `predictions.txt`。
## 参考文献
## References
1. <https://en.wikipedia.org/wiki/Click-through_rate>
2. <https://www.kaggle.com/c/avazu-ctr-prediction/data>
3. Cheng H T, Koc L, Harmsen J, et al. [Wide & deep learning for recommender systems](https://arxiv.org/pdf/1606.07792.pdf)[C]//Proceedings of the 1st Workshop on Deep Learning for Recommender Systems. ACM, 2016: 7-10.
......
......@@ -14,8 +14,8 @@
- [Hyper-parameters Tuning](#hyper-parameters-tuning)
- [Training for Mandarin Language](#training-for-mandarin-language)
- [Trying Live Demo with Your Own Voice](#trying-live-demo-with-your-own-voice)
- [Experiments and Benchmarks](#experiments-and-benchmarks)
- [Released Models](#released-models)
- [Experiments and Benchmarks](#experiments-and-benchmarks)
- [Questions and Help](#questions-and-help)
## Prerequisites
......@@ -419,13 +419,68 @@ python deploy/demo_server.py --help
python deploy/demo_client.py --help
```
## Released Models
#### Speech Model Released
Language | Model Name | Training Data | Training Hours
:-----------: | :------------: | :----------: | -------:
English | [LibriSpeech Model](http://cloud.dlnel.org/filepub/?uuid=17404caf-cf19-492f-9707-1fad07c19aae) | [LibriSpeech Dataset](http://www.openslr.org/12/) | 960 h
English | [Internal English Model](to-be-added) | Baidu English Dataset | 8000 h
Mandarin | [Aishell Model](http://cloud.dlnel.org/filepub/?uuid=6c83b9d8-3255-4adf-9726-0fe0be3d0274) | [Aishell Dataset](http://www.openslr.org/33/) | 151 h
Mandarin | [Internal Mandarin Model](to-be-added) | Baidu Mandarin Dataset | 2917 h
#### Language Model Released
Language Model | Training Data | Token-based | Size | Filter Configuraiton
:-------------:| :------------:| :-----: | -----: | -----------------:
[English LM (Median)](http://paddlepaddle.bj.bcebos.com/model_zoo/speech/common_crawl_00.prune01111.trie.klm) | To Be Added | Word-based | 8.3 GB | To Be Added
[English LM (Big)](to-be-added) | To Be Added | Word-based | X.X GB | To Be Added
[Mandarin LM (Median)](http://cloud.dlnel.org/filepub/?uuid=d21861e4-4ed6-45bb-ad8e-ae417a43195e) | To Be Added | Character-based | 2.8 GB | To Be Added
[Mandarin LM (Big)](to-be-added) | To Be Added | Character-based | X.X GB | To Be Added
## Experiments and Benchmarks
TODO: to be added
#### English Model Evaluation (Word Error Rate)
## Released Models
Test Set | LibriSpeech Model | Internal English Model
:---------------------: | :---------------: | :-------------------:
LibriSpeech-Test-Clean | 7.9 | X.X
LibriSpeech-Test-Other | X.X | X.X
VoxForge-Test | X.X | X.X
Baidu-English-Test | X.X | X.X
TODO: to be added
#### English Model Evaluation (Character Error Rate)
Test Set | LibriSpeech Model | Internal English Model
:---------------------: | :---------------: | :-------------------:
LibriSpeech-Test-Clean | X.X | X.X
LibriSpeech-Test-Other | X.X | X.X
VoxForge-Test | X.X | X.X
Baidu-English-Test | X.X | X.X
#### Mandarin Model Evaluation (Character Error Rate)
Test Set | Aishell Model | Internal Mandarin Model
:---------------------: | :---------------: | :-------------------:
Aishell-Test | X.X | X.X
Baidu-Mandarin-Test | X.X | X.X
#### Acceleration with Multi-GPUs
We compare the training time with 1, 2, 4, 8, 16 Tesla K40m GPUs (with a subset of LibriSpeech samples whose audio durations are between 6.0 and 7.0 seconds). And it shows that a **near-linear** acceleration with multiple GPUs has been achieved. In the following figure, the time (in seconds) used for training is plotted on the blue bars.
<img src="docs/images/multi_gpu_speedup.png" width=450><br/>
| # of GPU | Acceleration Rate |
| -------- | --------------: |
| 1 | 1.00 X |
| 2 | 1.97 X |
| 4 | 3.74 X |
| 8 | 6.21 X |
|16 | 10.70 X |
`tools/profile.sh` provides such a profiling tool.
## Questions and Help
......
#! /usr/bin/bash
#! /usr/bin/env bash
TRAIN_MANIFEST="cloud/cloud_manifests/cloud.manifest.train"
DEV_MANIFEST="cloud/cloud_manifests/cloud.manifest.dev"
......
#! /usr/bin/bash
#! /usr/bin/env bash
TRAIN_MANIFEST=$1
DEV_MANIFEST=$2
......@@ -15,6 +15,8 @@ python ./cloud/split_data.py \
--in_manifest_path=${DEV_MANIFEST} \
--out_manifest_path='/local.manifest.dev'
mkdir ./logs
python -u train.py \
--batch_size=${BATCH_SIZE} \
--trainer_count=${NUM_GPU} \
......@@ -35,10 +37,10 @@ python -u train.py \
--train_manifest='/local.manifest.train' \
--dev_manifest='/local.manifest.dev' \
--mean_std_path='data/librispeech/mean_std.npz' \
--vocab_path='data/librispeech/eng_vocab.txt' \
--vocab_path='data/librispeech/vocab.txt' \
--output_model_dir='./checkpoints' \
--output_model_dir=${MODEL_PATH} \
--augment_conf_path='conf/augmentation.config' \
--specgram_type='linear' \
--shuffle_method='batch_shuffle_clipped' \
2>&1 | tee ./log/train.log
2>&1 | tee ./logs/train.log
#! /usr/bin/bash
#! /usr/bin/env bash
mkdir cloud_manifests
......
......@@ -42,8 +42,8 @@ def ctc_greedy_decoder(probs_seq, vocabulary):
def ctc_beam_search_decoder(probs_seq,
beam_size,
vocabulary,
blank_id,
cutoff_prob=1.0,
cutoff_top_n=40,
ext_scoring_func=None,
nproc=False):
"""CTC Beam search decoder.
......@@ -66,8 +66,6 @@ def ctc_beam_search_decoder(probs_seq,
:type beam_size: int
:param vocabulary: Vocabulary list.
:type vocabulary: list
:param blank_id: ID of blank.
:type blank_id: int
:param cutoff_prob: Cutoff probability in pruning,
default 1.0, no pruning.
:type cutoff_prob: float
......@@ -87,9 +85,8 @@ def ctc_beam_search_decoder(probs_seq,
raise ValueError("The shape of prob_seq does not match with the "
"shape of the vocabulary.")
# blank_id check
if not blank_id < len(probs_seq[0]):
raise ValueError("blank_id shouldn't be greater than probs dimension")
# blank_id assign
blank_id = len(vocabulary)
# If the decoder called in the multiprocesses, then use the global scorer
# instantiated in ctc_beam_search_decoder_batch().
......@@ -114,7 +111,7 @@ def ctc_beam_search_decoder(probs_seq,
prob_idx = list(enumerate(probs_seq[time_step]))
cutoff_len = len(prob_idx)
#If pruning is enabled
if cutoff_prob < 1.0:
if cutoff_prob < 1.0 or cutoff_top_n < cutoff_len:
prob_idx = sorted(prob_idx, key=lambda asd: asd[1], reverse=True)
cutoff_len, cum_prob = 0, 0.0
for i in xrange(len(prob_idx)):
......@@ -122,6 +119,7 @@ def ctc_beam_search_decoder(probs_seq,
cutoff_len += 1
if cum_prob >= cutoff_prob:
break
cutoff_len = min(cutoff_len, cutoff_top_n)
prob_idx = prob_idx[0:cutoff_len]
for l in prefix_set_prev:
......@@ -191,9 +189,9 @@ def ctc_beam_search_decoder(probs_seq,
def ctc_beam_search_decoder_batch(probs_split,
beam_size,
vocabulary,
blank_id,
num_processes,
cutoff_prob=1.0,
cutoff_top_n=40,
ext_scoring_func=None):
"""CTC beam search decoder using multiple processes.
......@@ -204,8 +202,6 @@ def ctc_beam_search_decoder_batch(probs_split,
:type beam_size: int
:param vocabulary: Vocabulary list.
:type vocabulary: list
:param blank_id: ID of blank.
:type blank_id: int
:param num_processes: Number of parallel processes.
:type num_processes: int
:param cutoff_prob: Cutoff probability in pruning,
......@@ -232,8 +228,8 @@ def ctc_beam_search_decoder_batch(probs_split,
pool = multiprocessing.Pool(processes=num_processes)
results = []
for i, probs_list in enumerate(probs_split):
args = (probs_list, beam_size, vocabulary, blank_id, cutoff_prob, None,
nproc)
args = (probs_list, beam_size, vocabulary, cutoff_prob, cutoff_top_n,
None, nproc)
results.append(pool.apply_async(ctc_beam_search_decoder, args))
pool.close()
......
......@@ -8,7 +8,7 @@ import kenlm
import numpy as np
class LmScorer(object):
class Scorer(object):
"""External scorer to evaluate a prefix or whole sentence in
beam search decoding, including the score from n-gram language
model and word count.
......
#include "ctc_beam_search_decoder.h"
#include <algorithm>
#include <cmath>
#include <iostream>
#include <limits>
#include <map>
#include <utility>
#include "ThreadPool.h"
#include "fst/fstlib.h"
#include "decoder_utils.h"
#include "path_trie.h"
using FSTMATCH = fst::SortedMatcher<fst::StdVectorFst>;
std::vector<std::pair<double, std::string>> ctc_beam_search_decoder(
const std::vector<std::vector<double>> &probs_seq,
const std::vector<std::string> &vocabulary,
size_t beam_size,
double cutoff_prob,
size_t cutoff_top_n,
Scorer *ext_scorer) {
// dimension check
size_t num_time_steps = probs_seq.size();
for (size_t i = 0; i < num_time_steps; ++i) {
VALID_CHECK_EQ(probs_seq[i].size(),
vocabulary.size() + 1,
"The shape of probs_seq does not match with "
"the shape of the vocabulary");
}
// assign blank id
size_t blank_id = vocabulary.size();
// assign space id
auto it = std::find(vocabulary.begin(), vocabulary.end(), " ");
int space_id = it - vocabulary.begin();
// if no space in vocabulary
if ((size_t)space_id >= vocabulary.size()) {
space_id = -2;
}
// init prefixes' root
PathTrie root;
root.score = root.log_prob_b_prev = 0.0;
std::vector<PathTrie *> prefixes;
prefixes.push_back(&root);
if (ext_scorer != nullptr && !ext_scorer->is_character_based()) {
auto fst_dict = static_cast<fst::StdVectorFst *>(ext_scorer->dictionary);
fst::StdVectorFst *dict_ptr = fst_dict->Copy(true);
root.set_dictionary(dict_ptr);
auto matcher = std::make_shared<FSTMATCH>(*dict_ptr, fst::MATCH_INPUT);
root.set_matcher(matcher);
}
// prefix search over time
for (size_t time_step = 0; time_step < num_time_steps; ++time_step) {
auto &prob = probs_seq[time_step];
float min_cutoff = -NUM_FLT_INF;
bool full_beam = false;
if (ext_scorer != nullptr) {
size_t num_prefixes = std::min(prefixes.size(), beam_size);
std::sort(
prefixes.begin(), prefixes.begin() + num_prefixes, prefix_compare);
min_cutoff = prefixes[num_prefixes - 1]->score +
std::log(prob[blank_id]) - std::max(0.0, ext_scorer->beta);
full_beam = (num_prefixes == beam_size);
}
std::vector<std::pair<size_t, float>> log_prob_idx =
get_pruned_log_probs(prob, cutoff_prob, cutoff_top_n);
// loop over chars
for (size_t index = 0; index < log_prob_idx.size(); index++) {
auto c = log_prob_idx[index].first;
auto log_prob_c = log_prob_idx[index].second;
for (size_t i = 0; i < prefixes.size() && i < beam_size; ++i) {
auto prefix = prefixes[i];
if (full_beam && log_prob_c + prefix->score < min_cutoff) {
break;
}
// blank
if (c == blank_id) {
prefix->log_prob_b_cur =
log_sum_exp(prefix->log_prob_b_cur, log_prob_c + prefix->score);
continue;
}
// repeated character
if (c == prefix->character) {
prefix->log_prob_nb_cur = log_sum_exp(
prefix->log_prob_nb_cur, log_prob_c + prefix->log_prob_nb_prev);
}
// get new prefix
auto prefix_new = prefix->get_path_trie(c);
if (prefix_new != nullptr) {
float log_p = -NUM_FLT_INF;
if (c == prefix->character &&
prefix->log_prob_b_prev > -NUM_FLT_INF) {
log_p = log_prob_c + prefix->log_prob_b_prev;
} else if (c != prefix->character) {
log_p = log_prob_c + prefix->score;
}
// language model scoring
if (ext_scorer != nullptr &&
(c == space_id || ext_scorer->is_character_based())) {
PathTrie *prefix_toscore = nullptr;
// skip scoring the space
if (ext_scorer->is_character_based()) {
prefix_toscore = prefix_new;
} else {
prefix_toscore = prefix;
}
double score = 0.0;
std::vector<std::string> ngram;
ngram = ext_scorer->make_ngram(prefix_toscore);
score = ext_scorer->get_log_cond_prob(ngram) * ext_scorer->alpha;
log_p += score;
log_p += ext_scorer->beta;
}
prefix_new->log_prob_nb_cur =
log_sum_exp(prefix_new->log_prob_nb_cur, log_p);
}
} // end of loop over prefix
} // end of loop over vocabulary
prefixes.clear();
// update log probs
root.iterate_to_vec(prefixes);
// only preserve top beam_size prefixes
if (prefixes.size() >= beam_size) {
std::nth_element(prefixes.begin(),
prefixes.begin() + beam_size,
prefixes.end(),
prefix_compare);
for (size_t i = beam_size; i < prefixes.size(); ++i) {
prefixes[i]->remove();
}
}
} // end of loop over time
// compute aproximate ctc score as the return score, without affecting the
// return order of decoding result. To delete when decoder gets stable.
for (size_t i = 0; i < beam_size && i < prefixes.size(); ++i) {
double approx_ctc = prefixes[i]->score;
if (ext_scorer != nullptr) {
std::vector<int> output;
prefixes[i]->get_path_vec(output);
auto prefix_length = output.size();
auto words = ext_scorer->split_labels(output);
// remove word insert
approx_ctc = approx_ctc - prefix_length * ext_scorer->beta;
// remove language model weight:
approx_ctc -= (ext_scorer->get_sent_log_prob(words)) * ext_scorer->alpha;
}
prefixes[i]->approx_ctc = approx_ctc;
}
return get_beam_search_result(prefixes, vocabulary, beam_size);
}
std::vector<std::vector<std::pair<double, std::string>>>
ctc_beam_search_decoder_batch(
const std::vector<std::vector<std::vector<double>>> &probs_split,
const std::vector<std::string> &vocabulary,
size_t beam_size,
size_t num_processes,
double cutoff_prob,
size_t cutoff_top_n,
Scorer *ext_scorer) {
VALID_CHECK_GT(num_processes, 0, "num_processes must be nonnegative!");
// thread pool
ThreadPool pool(num_processes);
// number of samples
size_t batch_size = probs_split.size();
// enqueue the tasks of decoding
std::vector<std::future<std::vector<std::pair<double, std::string>>>> res;
for (size_t i = 0; i < batch_size; ++i) {
res.emplace_back(pool.enqueue(ctc_beam_search_decoder,
probs_split[i],
vocabulary,
beam_size,
cutoff_prob,
cutoff_top_n,
ext_scorer));
}
// get decoding results
std::vector<std::vector<std::pair<double, std::string>>> batch_results;
for (size_t i = 0; i < batch_size; ++i) {
batch_results.emplace_back(res[i].get());
}
return batch_results;
}
#ifndef CTC_BEAM_SEARCH_DECODER_H_
#define CTC_BEAM_SEARCH_DECODER_H_
#include <string>
#include <utility>
#include <vector>
#include "scorer.h"
/* CTC Beam Search Decoder
* Parameters:
* probs_seq: 2-D vector that each element is a vector of probabilities
* over vocabulary of one time step.
* vocabulary: A vector of vocabulary.
* beam_size: The width of beam search.
* cutoff_prob: Cutoff probability for pruning.
* cutoff_top_n: Cutoff number for pruning.
* ext_scorer: External scorer to evaluate a prefix, which consists of
* n-gram language model scoring and word insertion term.
* Default null, decoding the input sample without scorer.
* Return:
* A vector that each element is a pair of score and decoding result,
* in desending order.
*/
std::vector<std::pair<double, std::string>> ctc_beam_search_decoder(
const std::vector<std::vector<double>> &probs_seq,
const std::vector<std::string> &vocabulary,
size_t beam_size,
double cutoff_prob = 1.0,
size_t cutoff_top_n = 40,
Scorer *ext_scorer = nullptr);
/* CTC Beam Search Decoder for batch data
* Parameters:
* probs_seq: 3-D vector that each element is a 2-D vector that can be used
* by ctc_beam_search_decoder().
* vocabulary: A vector of vocabulary.
* beam_size: The width of beam search.
* num_processes: Number of threads for beam search.
* cutoff_prob: Cutoff probability for pruning.
* cutoff_top_n: Cutoff number for pruning.
* ext_scorer: External scorer to evaluate a prefix, which consists of
* n-gram language model scoring and word insertion term.
* Default null, decoding the input sample without scorer.
* Return:
* A 2-D vector that each element is a vector of beam search decoding
* result for one audio sample.
*/
std::vector<std::vector<std::pair<double, std::string>>>
ctc_beam_search_decoder_batch(
const std::vector<std::vector<std::vector<double>>> &probs_split,
const std::vector<std::string> &vocabulary,
size_t beam_size,
size_t num_processes,
double cutoff_prob = 1.0,
size_t cutoff_top_n = 40,
Scorer *ext_scorer = nullptr);
#endif // CTC_BEAM_SEARCH_DECODER_H_
#include "ctc_greedy_decoder.h"
#include "decoder_utils.h"
std::string ctc_greedy_decoder(
const std::vector<std::vector<double>> &probs_seq,
const std::vector<std::string> &vocabulary) {
// dimension check
size_t num_time_steps = probs_seq.size();
for (size_t i = 0; i < num_time_steps; ++i) {
VALID_CHECK_EQ(probs_seq[i].size(),
vocabulary.size() + 1,
"The shape of probs_seq does not match with "
"the shape of the vocabulary");
}
size_t blank_id = vocabulary.size();
std::vector<size_t> max_idx_vec(num_time_steps, 0);
std::vector<size_t> idx_vec;
for (size_t i = 0; i < num_time_steps; ++i) {
double max_prob = 0.0;
size_t max_idx = 0;
const std::vector<double> &probs_step = probs_seq[i];
for (size_t j = 0; j < probs_step.size(); ++j) {
if (max_prob < probs_step[j]) {
max_idx = j;
max_prob = probs_step[j];
}
}
// id with maximum probability in current time step
max_idx_vec[i] = max_idx;
// deduplicate
if ((i == 0) || ((i > 0) && max_idx_vec[i] != max_idx_vec[i - 1])) {
idx_vec.push_back(max_idx_vec[i]);
}
}
std::string best_path_result;
for (size_t i = 0; i < idx_vec.size(); ++i) {
if (idx_vec[i] != blank_id) {
best_path_result += vocabulary[idx_vec[i]];
}
}
return best_path_result;
}
#ifndef CTC_GREEDY_DECODER_H
#define CTC_GREEDY_DECODER_H
#include <string>
#include <vector>
/* CTC Greedy (Best Path) Decoder
*
* Parameters:
* probs_seq: 2-D vector that each element is a vector of probabilities
* over vocabulary of one time step.
* vocabulary: A vector of vocabulary.
* Return:
* The decoding result in string
*/
std::string ctc_greedy_decoder(
const std::vector<std::vector<double>>& probs_seq,
const std::vector<std::string>& vocabulary);
#endif // CTC_GREEDY_DECODER_H
#include "decoder_utils.h"
#include <algorithm>
#include <cmath>
#include <limits>
std::vector<std::pair<size_t, float>> get_pruned_log_probs(
const std::vector<double> &prob_step,
double cutoff_prob,
size_t cutoff_top_n) {
std::vector<std::pair<int, double>> prob_idx;
for (size_t i = 0; i < prob_step.size(); ++i) {
prob_idx.push_back(std::pair<int, double>(i, prob_step[i]));
}
// pruning of vacobulary
size_t cutoff_len = prob_step.size();
if (cutoff_prob < 1.0 || cutoff_top_n < cutoff_len) {
std::sort(
prob_idx.begin(), prob_idx.end(), pair_comp_second_rev<int, double>);
if (cutoff_prob < 1.0) {
double cum_prob = 0.0;
cutoff_len = 0;
for (size_t i = 0; i < prob_idx.size(); ++i) {
cum_prob += prob_idx[i].second;
cutoff_len += 1;
if (cum_prob >= cutoff_prob || cutoff_len >= cutoff_top_n) break;
}
}
prob_idx = std::vector<std::pair<int, double>>(
prob_idx.begin(), prob_idx.begin() + cutoff_len);
}
std::vector<std::pair<size_t, float>> log_prob_idx;
for (size_t i = 0; i < cutoff_len; ++i) {
log_prob_idx.push_back(std::pair<int, float>(
prob_idx[i].first, log(prob_idx[i].second + NUM_FLT_MIN)));
}
return log_prob_idx;
}
std::vector<std::pair<double, std::string>> get_beam_search_result(
const std::vector<PathTrie *> &prefixes,
const std::vector<std::string> &vocabulary,
size_t beam_size) {
// allow for the post processing
std::vector<PathTrie *> space_prefixes;
if (space_prefixes.empty()) {
for (size_t i = 0; i < beam_size && i < prefixes.size(); ++i) {
space_prefixes.push_back(prefixes[i]);
}
}
std::sort(space_prefixes.begin(), space_prefixes.end(), prefix_compare);
std::vector<std::pair<double, std::string>> output_vecs;
for (size_t i = 0; i < beam_size && i < space_prefixes.size(); ++i) {
std::vector<int> output;
space_prefixes[i]->get_path_vec(output);
// convert index to string
std::string output_str;
for (size_t j = 0; j < output.size(); j++) {
output_str += vocabulary[output[j]];
}
std::pair<double, std::string> output_pair(-space_prefixes[i]->approx_ctc,
output_str);
output_vecs.emplace_back(output_pair);
}
return output_vecs;
}
size_t get_utf8_str_len(const std::string &str) {
size_t str_len = 0;
for (char c : str) {
str_len += ((c & 0xc0) != 0x80);
}
return str_len;
}
std::vector<std::string> split_utf8_str(const std::string &str) {
std::vector<std::string> result;
std::string out_str;
for (char c : str) {
if ((c & 0xc0) != 0x80) // new UTF-8 character
{
if (!out_str.empty()) {
result.push_back(out_str);
out_str.clear();
}
}
out_str.append(1, c);
}
result.push_back(out_str);
return result;
}
std::vector<std::string> split_str(const std::string &s,
const std::string &delim) {
std::vector<std::string> result;
std::size_t start = 0, delim_len = delim.size();
while (true) {
std::size_t end = s.find(delim, start);
if (end == std::string::npos) {
if (start < s.size()) {
result.push_back(s.substr(start));
}
break;
}
if (end > start) {
result.push_back(s.substr(start, end - start));
}
start = end + delim_len;
}
return result;
}
bool prefix_compare(const PathTrie *x, const PathTrie *y) {
if (x->score == y->score) {
if (x->character == y->character) {
return false;
} else {
return (x->character < y->character);
}
} else {
return x->score > y->score;
}
}
void add_word_to_fst(const std::vector<int> &word,
fst::StdVectorFst *dictionary) {
if (dictionary->NumStates() == 0) {
fst::StdVectorFst::StateId start = dictionary->AddState();
assert(start == 0);
dictionary->SetStart(start);
}
fst::StdVectorFst::StateId src = dictionary->Start();
fst::StdVectorFst::StateId dst;
for (auto c : word) {
dst = dictionary->AddState();
dictionary->AddArc(src, fst::StdArc(c, c, 0, dst));
src = dst;
}
dictionary->SetFinal(dst, fst::StdArc::Weight::One());
}
bool add_word_to_dictionary(
const std::string &word,
const std::unordered_map<std::string, int> &char_map,
bool add_space,
int SPACE_ID,
fst::StdVectorFst *dictionary) {
auto characters = split_utf8_str(word);
std::vector<int> int_word;
for (auto &c : characters) {
if (c == " ") {
int_word.push_back(SPACE_ID);
} else {
auto int_c = char_map.find(c);
if (int_c != char_map.end()) {
int_word.push_back(int_c->second);
} else {
return false; // return without adding
}
}
}
if (add_space) {
int_word.push_back(SPACE_ID);
}
add_word_to_fst(int_word, dictionary);
return true; // return with successful adding
}
#ifndef DECODER_UTILS_H_
#define DECODER_UTILS_H_
#include <utility>
#include "fst/log.h"
#include "path_trie.h"
const float NUM_FLT_INF = std::numeric_limits<float>::max();
const float NUM_FLT_MIN = std::numeric_limits<float>::min();
// inline function for validation check
inline void check(
bool x, const char *expr, const char *file, int line, const char *err) {
if (!x) {
std::cout << "[" << file << ":" << line << "] ";
LOG(FATAL) << "\"" << expr << "\" check failed. " << err;
}
}
#define VALID_CHECK(x, info) \
check(static_cast<bool>(x), #x, __FILE__, __LINE__, info)
#define VALID_CHECK_EQ(x, y, info) VALID_CHECK((x) == (y), info)
#define VALID_CHECK_GT(x, y, info) VALID_CHECK((x) > (y), info)
#define VALID_CHECK_LT(x, y, info) VALID_CHECK((x) < (y), info)
// Function template for comparing two pairs
template <typename T1, typename T2>
bool pair_comp_first_rev(const std::pair<T1, T2> &a,
const std::pair<T1, T2> &b) {
return a.first > b.first;
}
// Function template for comparing two pairs
template <typename T1, typename T2>
bool pair_comp_second_rev(const std::pair<T1, T2> &a,
const std::pair<T1, T2> &b) {
return a.second > b.second;
}
// Return the sum of two probabilities in log scale
template <typename T>
T log_sum_exp(const T &x, const T &y) {
static T num_min = -std::numeric_limits<T>::max();
if (x <= num_min) return y;
if (y <= num_min) return x;
T xmax = std::max(x, y);
return std::log(std::exp(x - xmax) + std::exp(y - xmax)) + xmax;
}
// Get pruned probability vector for each time step's beam search
std::vector<std::pair<size_t, float>> get_pruned_log_probs(
const std::vector<double> &prob_step,
double cutoff_prob,
size_t cutoff_top_n);
// Get beam search result from prefixes in trie tree
std::vector<std::pair<double, std::string>> get_beam_search_result(
const std::vector<PathTrie *> &prefixes,
const std::vector<std::string> &vocabulary,
size_t beam_size);
// Functor for prefix comparsion
bool prefix_compare(const PathTrie *x, const PathTrie *y);
/* Get length of utf8 encoding string
* See: http://stackoverflow.com/a/4063229
*/
size_t get_utf8_str_len(const std::string &str);
/* Split a string into a list of strings on a given string
* delimiter. NB: delimiters on beginning / end of string are
* trimmed. Eg, "FooBarFoo" split on "Foo" returns ["Bar"].
*/
std::vector<std::string> split_str(const std::string &s,
const std::string &delim);
/* Splits string into vector of strings representing
* UTF-8 characters (not same as chars)
*/
std::vector<std::string> split_utf8_str(const std::string &str);
// Add a word in index to the dicionary of fst
void add_word_to_fst(const std::vector<int> &word,
fst::StdVectorFst *dictionary);
// Add a word in string to dictionary
bool add_word_to_dictionary(
const std::string &word,
const std::unordered_map<std::string, int> &char_map,
bool add_space,
int SPACE_ID,
fst::StdVectorFst *dictionary);
#endif // DECODER_UTILS_H
%module swig_decoders
%{
#include "scorer.h"
#include "ctc_greedy_decoder.h"
#include "ctc_beam_search_decoder.h"
#include "decoder_utils.h"
%}
%include "std_vector.i"
%include "std_pair.i"
%include "std_string.i"
%import "decoder_utils.h"
namespace std {
%template(DoubleVector) std::vector<double>;
%template(IntVector) std::vector<int>;
%template(StringVector) std::vector<std::string>;
%template(VectorOfStructVector) std::vector<std::vector<double> >;
%template(FloatVector) std::vector<float>;
%template(Pair) std::pair<float, std::string>;
%template(PairFloatStringVector) std::vector<std::pair<float, std::string> >;
%template(PairDoubleStringVector) std::vector<std::pair<double, std::string> >;
%template(PairDoubleStringVector2) std::vector<std::vector<std::pair<double, std::string> > >;
%template(DoubleVector3) std::vector<std::vector<std::vector<double> > >;
}
%template(IntDoublePairCompSecondRev) pair_comp_second_rev<int, double>;
%template(StringDoublePairCompSecondRev) pair_comp_second_rev<std::string, double>;
%template(DoubleStringPairCompFirstRev) pair_comp_first_rev<double, std::string>;
%include "scorer.h"
%include "ctc_greedy_decoder.h"
%include "ctc_beam_search_decoder.h"
#include "path_trie.h"
#include <algorithm>
#include <limits>
#include <memory>
#include <utility>
#include <vector>
#include "decoder_utils.h"
PathTrie::PathTrie() {
log_prob_b_prev = -NUM_FLT_INF;
log_prob_nb_prev = -NUM_FLT_INF;
log_prob_b_cur = -NUM_FLT_INF;
log_prob_nb_cur = -NUM_FLT_INF;
score = -NUM_FLT_INF;
ROOT_ = -1;
character = ROOT_;
exists_ = true;
parent = nullptr;
dictionary_ = nullptr;
dictionary_state_ = 0;
has_dictionary_ = false;
matcher_ = nullptr;
}
PathTrie::~PathTrie() {
for (auto child : children_) {
delete child.second;
}
}
PathTrie* PathTrie::get_path_trie(int new_char, bool reset) {
auto child = children_.begin();
for (child = children_.begin(); child != children_.end(); ++child) {
if (child->first == new_char) {
break;
}
}
if (child != children_.end()) {
if (!child->second->exists_) {
child->second->exists_ = true;
child->second->log_prob_b_prev = -NUM_FLT_INF;
child->second->log_prob_nb_prev = -NUM_FLT_INF;
child->second->log_prob_b_cur = -NUM_FLT_INF;
child->second->log_prob_nb_cur = -NUM_FLT_INF;
}
return (child->second);
} else {
if (has_dictionary_) {
matcher_->SetState(dictionary_state_);
bool found = matcher_->Find(new_char);
if (!found) {
// Adding this character causes word outside dictionary
auto FSTZERO = fst::TropicalWeight::Zero();
auto final_weight = dictionary_->Final(dictionary_state_);
bool is_final = (final_weight != FSTZERO);
if (is_final && reset) {
dictionary_state_ = dictionary_->Start();
}
return nullptr;
} else {
PathTrie* new_path = new PathTrie;
new_path->character = new_char;
new_path->parent = this;
new_path->dictionary_ = dictionary_;
new_path->dictionary_state_ = matcher_->Value().nextstate;
new_path->has_dictionary_ = true;
new_path->matcher_ = matcher_;
children_.push_back(std::make_pair(new_char, new_path));
return new_path;
}
} else {
PathTrie* new_path = new PathTrie;
new_path->character = new_char;
new_path->parent = this;
children_.push_back(std::make_pair(new_char, new_path));
return new_path;
}
}
}
PathTrie* PathTrie::get_path_vec(std::vector<int>& output) {
return get_path_vec(output, ROOT_);
}
PathTrie* PathTrie::get_path_vec(std::vector<int>& output,
int stop,
size_t max_steps) {
if (character == stop || character == ROOT_ || output.size() == max_steps) {
std::reverse(output.begin(), output.end());
return this;
} else {
output.push_back(character);
return parent->get_path_vec(output, stop, max_steps);
}
}
void PathTrie::iterate_to_vec(std::vector<PathTrie*>& output) {
if (exists_) {
log_prob_b_prev = log_prob_b_cur;
log_prob_nb_prev = log_prob_nb_cur;
log_prob_b_cur = -NUM_FLT_INF;
log_prob_nb_cur = -NUM_FLT_INF;
score = log_sum_exp(log_prob_b_prev, log_prob_nb_prev);
output.push_back(this);
}
for (auto child : children_) {
child.second->iterate_to_vec(output);
}
}
void PathTrie::remove() {
exists_ = false;
if (children_.size() == 0) {
auto child = parent->children_.begin();
for (child = parent->children_.begin(); child != parent->children_.end();
++child) {
if (child->first == character) {
parent->children_.erase(child);
break;
}
}
if (parent->children_.size() == 0 && !parent->exists_) {
parent->remove();
}
delete this;
}
}
void PathTrie::set_dictionary(fst::StdVectorFst* dictionary) {
dictionary_ = dictionary;
dictionary_state_ = dictionary->Start();
has_dictionary_ = true;
}
using FSTMATCH = fst::SortedMatcher<fst::StdVectorFst>;
void PathTrie::set_matcher(std::shared_ptr<FSTMATCH> matcher) {
matcher_ = matcher;
}
#ifndef PATH_TRIE_H
#define PATH_TRIE_H
#include <algorithm>
#include <limits>
#include <memory>
#include <utility>
#include <vector>
#include "fst/fstlib.h"
/* Trie tree for prefix storing and manipulating, with a dictionary in
* finite-state transducer for spelling correction.
*/
class PathTrie {
public:
PathTrie();
~PathTrie();
// get new prefix after appending new char
PathTrie* get_path_trie(int new_char, bool reset = true);
// get the prefix in index from root to current node
PathTrie* get_path_vec(std::vector<int>& output);
// get the prefix in index from some stop node to current nodel
PathTrie* get_path_vec(std::vector<int>& output,
int stop,
size_t max_steps = std::numeric_limits<size_t>::max());
// update log probs
void iterate_to_vec(std::vector<PathTrie*>& output);
// set dictionary for FST
void set_dictionary(fst::StdVectorFst* dictionary);
void set_matcher(std::shared_ptr<fst::SortedMatcher<fst::StdVectorFst>>);
bool is_empty() { return ROOT_ == character; }
// remove current path from root
void remove();
float log_prob_b_prev;
float log_prob_nb_prev;
float log_prob_b_cur;
float log_prob_nb_cur;
float score;
float approx_ctc;
int character;
PathTrie* parent;
private:
int ROOT_;
bool exists_;
bool has_dictionary_;
std::vector<std::pair<int, PathTrie*>> children_;
// pointer to dictionary of FST
fst::StdVectorFst* dictionary_;
fst::StdVectorFst::StateId dictionary_state_;
// true if finding ars in FST
std::shared_ptr<fst::SortedMatcher<fst::StdVectorFst>> matcher_;
};
#endif // PATH_TRIE_H
#include "scorer.h"
#include <unistd.h>
#include <iostream>
#include "lm/config.hh"
#include "lm/model.hh"
#include "lm/state.hh"
#include "util/string_piece.hh"
#include "util/tokenize_piece.hh"
#include "decoder_utils.h"
using namespace lm::ngram;
Scorer::Scorer(double alpha,
double beta,
const std::string& lm_path,
const std::vector<std::string>& vocab_list) {
this->alpha = alpha;
this->beta = beta;
dictionary = nullptr;
is_character_based_ = true;
language_model_ = nullptr;
max_order_ = 0;
dict_size_ = 0;
SPACE_ID_ = -1;
setup(lm_path, vocab_list);
}
Scorer::~Scorer() {
if (language_model_ != nullptr) {
delete static_cast<lm::base::Model*>(language_model_);
}
if (dictionary != nullptr) {
delete static_cast<fst::StdVectorFst*>(dictionary);
}
}
void Scorer::setup(const std::string& lm_path,
const std::vector<std::string>& vocab_list) {
// load language model
load_lm(lm_path);
// set char map for scorer
set_char_map(vocab_list);
// fill the dictionary for FST
if (!is_character_based()) {
fill_dictionary(true);
}
}
void Scorer::load_lm(const std::string& lm_path) {
const char* filename = lm_path.c_str();
VALID_CHECK_EQ(access(filename, F_OK), 0, "Invalid language model path");
RetriveStrEnumerateVocab enumerate;
lm::ngram::Config config;
config.enumerate_vocab = &enumerate;
language_model_ = lm::ngram::LoadVirtual(filename, config);
max_order_ = static_cast<lm::base::Model*>(language_model_)->Order();
vocabulary_ = enumerate.vocabulary;
for (size_t i = 0; i < vocabulary_.size(); ++i) {
if (is_character_based_ && vocabulary_[i] != UNK_TOKEN &&
vocabulary_[i] != START_TOKEN && vocabulary_[i] != END_TOKEN &&
get_utf8_str_len(enumerate.vocabulary[i]) > 1) {
is_character_based_ = false;
}
}
}
double Scorer::get_log_cond_prob(const std::vector<std::string>& words) {
lm::base::Model* model = static_cast<lm::base::Model*>(language_model_);
double cond_prob;
lm::ngram::State state, tmp_state, out_state;
// avoid to inserting <s> in begin
model->NullContextWrite(&state);
for (size_t i = 0; i < words.size(); ++i) {
lm::WordIndex word_index = model->BaseVocabulary().Index(words[i]);
// encounter OOV
if (word_index == 0) {
return OOV_SCORE;
}
cond_prob = model->BaseScore(&state, word_index, &out_state);
tmp_state = state;
state = out_state;
out_state = tmp_state;
}
// return log10 prob
return cond_prob;
}
double Scorer::get_sent_log_prob(const std::vector<std::string>& words) {
std::vector<std::string> sentence;
if (words.size() == 0) {
for (size_t i = 0; i < max_order_; ++i) {
sentence.push_back(START_TOKEN);
}
} else {
for (size_t i = 0; i < max_order_ - 1; ++i) {
sentence.push_back(START_TOKEN);
}
sentence.insert(sentence.end(), words.begin(), words.end());
}
sentence.push_back(END_TOKEN);
return get_log_prob(sentence);
}
double Scorer::get_log_prob(const std::vector<std::string>& words) {
assert(words.size() > max_order_);
double score = 0.0;
for (size_t i = 0; i < words.size() - max_order_ + 1; ++i) {
std::vector<std::string> ngram(words.begin() + i,
words.begin() + i + max_order_);
score += get_log_cond_prob(ngram);
}
return score;
}
void Scorer::reset_params(float alpha, float beta) {
this->alpha = alpha;
this->beta = beta;
}
std::string Scorer::vec2str(const std::vector<int>& input) {
std::string word;
for (auto ind : input) {
word += char_list_[ind];
}
return word;
}
std::vector<std::string> Scorer::split_labels(const std::vector<int>& labels) {
if (labels.empty()) return {};
std::string s = vec2str(labels);
std::vector<std::string> words;
if (is_character_based_) {
words = split_utf8_str(s);
} else {
words = split_str(s, " ");
}
return words;
}
void Scorer::set_char_map(const std::vector<std::string>& char_list) {
char_list_ = char_list;
char_map_.clear();
for (size_t i = 0; i < char_list_.size(); i++) {
if (char_list_[i] == " ") {
SPACE_ID_ = i;
char_map_[' '] = i;
} else if (char_list_[i].size() == 1) {
char_map_[char_list_[i][0]] = i;
}
}
}
std::vector<std::string> Scorer::make_ngram(PathTrie* prefix) {
std::vector<std::string> ngram;
PathTrie* current_node = prefix;
PathTrie* new_node = nullptr;
for (int order = 0; order < max_order_; order++) {
std::vector<int> prefix_vec;
if (is_character_based_) {
new_node = current_node->get_path_vec(prefix_vec, SPACE_ID_, 1);
current_node = new_node;
} else {
new_node = current_node->get_path_vec(prefix_vec, SPACE_ID_);
current_node = new_node->parent; // Skipping spaces
}
// reconstruct word
std::string word = vec2str(prefix_vec);
ngram.push_back(word);
if (new_node->character == -1) {
// No more spaces, but still need order
for (int i = 0; i < max_order_ - order - 1; i++) {
ngram.push_back(START_TOKEN);
}
break;
}
}
std::reverse(ngram.begin(), ngram.end());
return ngram;
}
void Scorer::fill_dictionary(bool add_space) {
fst::StdVectorFst dictionary;
// First reverse char_list so ints can be accessed by chars
std::unordered_map<std::string, int> char_map;
for (size_t i = 0; i < char_list_.size(); i++) {
char_map[char_list_[i]] = i;
}
// For each unigram convert to ints and put in trie
int dict_size = 0;
for (const auto& word : vocabulary_) {
bool added = add_word_to_dictionary(
word, char_map, add_space, SPACE_ID_, &dictionary);
dict_size += added ? 1 : 0;
}
dict_size_ = dict_size;
/* Simplify FST
* This gets rid of "epsilon" transitions in the FST.
* These are transitions that don't require a string input to be taken.
* Getting rid of them is necessary to make the FST determinisitc, but
* can greatly increase the size of the FST
*/
fst::RmEpsilon(&dictionary);
fst::StdVectorFst* new_dict = new fst::StdVectorFst;
/* This makes the FST deterministic, meaning for any string input there's
* only one possible state the FST could be in. It is assumed our
* dictionary is deterministic when using it.
* (lest we'd have to check for multiple transitions at each state)
*/
fst::Determinize(dictionary, new_dict);
/* Finds the simplest equivalent fst. This is unnecessary but decreases
* memory usage of the dictionary
*/
fst::Minimize(new_dict);
this->dictionary = new_dict;
}
#ifndef SCORER_H_
#define SCORER_H_
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
#include "lm/enumerate_vocab.hh"
#include "lm/virtual_interface.hh"
#include "lm/word_index.hh"
#include "util/string_piece.hh"
#include "path_trie.h"
const double OOV_SCORE = -1000.0;
const std::string START_TOKEN = "<s>";
const std::string UNK_TOKEN = "<unk>";
const std::string END_TOKEN = "</s>";
// Implement a callback to retrive the dictionary of language model.
class RetriveStrEnumerateVocab : public lm::EnumerateVocab {
public:
RetriveStrEnumerateVocab() {}
void Add(lm::WordIndex index, const StringPiece &str) {
vocabulary.push_back(std::string(str.data(), str.length()));
}
std::vector<std::string> vocabulary;
};
/* External scorer to query score for n-gram or sentence, including language
* model scoring and word insertion.
*
* Example:
* Scorer scorer(alpha, beta, "path_of_language_model");
* scorer.get_log_cond_prob({ "WORD1", "WORD2", "WORD3" });
* scorer.get_sent_log_prob({ "WORD1", "WORD2", "WORD3" });
*/
class Scorer {
public:
Scorer(double alpha,
double beta,
const std::string &lm_path,
const std::vector<std::string> &vocabulary);
~Scorer();
double get_log_cond_prob(const std::vector<std::string> &words);
double get_sent_log_prob(const std::vector<std::string> &words);
// return the max order
size_t get_max_order() const { return max_order_; }
// return the dictionary size of language model
size_t get_dict_size() const { return dict_size_; }
// retrun true if the language model is character based
bool is_character_based() const { return is_character_based_; }
// reset params alpha & beta
void reset_params(float alpha, float beta);
// make ngram for a given prefix
std::vector<std::string> make_ngram(PathTrie *prefix);
// trransform the labels in index to the vector of words (word based lm) or
// the vector of characters (character based lm)
std::vector<std::string> split_labels(const std::vector<int> &labels);
// language model weight
double alpha;
// word insertion weight
double beta;
// pointer to the dictionary of FST
void *dictionary;
protected:
// necessary setup: load language model, set char map, fill FST's dictionary
void setup(const std::string &lm_path,
const std::vector<std::string> &vocab_list);
// load language model from given path
void load_lm(const std::string &lm_path);
// fill dictionary for FST
void fill_dictionary(bool add_space);
// set char map
void set_char_map(const std::vector<std::string> &char_list);
double get_log_prob(const std::vector<std::string> &words);
// translate the vector in index to string
std::string vec2str(const std::vector<int> &input);
private:
void *language_model_;
bool is_character_based_;
size_t max_order_;
size_t dict_size_;
int SPACE_ID_;
std::vector<std::string> char_list_;
std::unordered_map<char, int> char_map_;
std::vector<std::string> vocabulary_;
};
#endif // SCORER_H_
"""Script to build and install decoder package."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from setuptools import setup, Extension, distutils
import glob
import platform
import os, sys
import multiprocessing.pool
import argparse
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument(
"--num_processes",
default=1,
type=int,
help="Number of cpu processes to build package. (default: %(default)d)")
args = parser.parse_known_args()
# reconstruct sys.argv to pass to setup below
sys.argv = [sys.argv[0]] + args[1]
# monkey-patch for parallel compilation
# See: https://stackoverflow.com/a/13176803
def parallelCCompile(self,
sources,
output_dir=None,
macros=None,
include_dirs=None,
debug=0,
extra_preargs=None,
extra_postargs=None,
depends=None):
# those lines are copied from distutils.ccompiler.CCompiler directly
macros, objects, extra_postargs, pp_opts, build = self._setup_compile(
output_dir, macros, include_dirs, sources, depends, extra_postargs)
cc_args = self._get_cc_args(pp_opts, debug, extra_preargs)
# parallel code
def _single_compile(obj):
try:
src, ext = build[obj]
except KeyError:
return
self._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)
# convert to list, imap is evaluated on-demand
thread_pool = multiprocessing.pool.ThreadPool(args[0].num_processes)
list(thread_pool.imap(_single_compile, objects))
return objects
def compile_test(header, library):
dummy_path = os.path.join(os.path.dirname(__file__), "dummy")
command = "bash -c \"g++ -include " + header \
+ " -l" + library + " -x c++ - <<<'int main() {}' -o " \
+ dummy_path + " >/dev/null 2>/dev/null && rm " \
+ dummy_path + " 2>/dev/null\""
return os.system(command) == 0
# hack compile to support parallel compiling
distutils.ccompiler.CCompiler.compile = parallelCCompile
FILES = glob.glob('kenlm/util/*.cc') \
+ glob.glob('kenlm/lm/*.cc') \
+ glob.glob('kenlm/util/double-conversion/*.cc')
FILES += glob.glob('openfst-1.6.3/src/lib/*.cc')
# FILES + glob.glob('glog/src/*.cc')
FILES = [
fn for fn in FILES
if not (fn.endswith('main.cc') or fn.endswith('test.cc') or fn.endswith(
'unittest.cc'))
]
LIBS = ['stdc++']
if platform.system() != 'Darwin':
LIBS.append('rt')
ARGS = ['-O3', '-DNDEBUG', '-DKENLM_MAX_ORDER=6', '-std=c++11']
if compile_test('zlib.h', 'z'):
ARGS.append('-DHAVE_ZLIB')
LIBS.append('z')
if compile_test('bzlib.h', 'bz2'):
ARGS.append('-DHAVE_BZLIB')
LIBS.append('bz2')
if compile_test('lzma.h', 'lzma'):
ARGS.append('-DHAVE_XZLIB')
LIBS.append('lzma')
os.system('swig -python -c++ ./decoders.i')
decoders_module = [
Extension(
name='_swig_decoders',
sources=FILES + glob.glob('*.cxx') + glob.glob('*.cpp'),
language='c++',
include_dirs=[
'.',
'kenlm',
'openfst-1.6.3/src/include',
'ThreadPool',
#'glog/src'
],
libraries=LIBS,
extra_compile_args=ARGS)
]
setup(
name='swig_decoders',
version='0.1',
description="""CTC decoders""",
ext_modules=decoders_module,
py_modules=['swig_decoders'], )
#!/usr/bin/env bash
if [ ! -d kenlm ]; then
git clone https://github.com/luotao1/kenlm.git
echo -e "\n"
fi
if [ ! -d openfst-1.6.3 ]; then
echo "Download and extract openfst ..."
wget http://www.openfst.org/twiki/pub/FST/FstDownload/openfst-1.6.3.tar.gz
tar -xzvf openfst-1.6.3.tar.gz
echo -e "\n"
fi
if [ ! -d ThreadPool ]; then
git clone https://github.com/progschj/ThreadPool.git
echo -e "\n"
fi
echo "Install decoders ..."
python setup.py install --num_processes 4
"""Wrapper for various CTC decoders in SWIG."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import swig_decoders
class Scorer(swig_decoders.Scorer):
"""Wrapper for Scorer.
:param alpha: Parameter associated with language model. Don't use
language model when alpha = 0.
:type alpha: float
:param beta: Parameter associated with word count. Don't use word
count when beta = 0.
:type beta: float
:model_path: Path to load language model.
:type model_path: basestring
"""
def __init__(self, alpha, beta, model_path, vocabulary):
swig_decoders.Scorer.__init__(self, alpha, beta, model_path, vocabulary)
def ctc_greedy_decoder(probs_seq, vocabulary):
"""Wrapper for ctc best path decoder in swig.
:param probs_seq: 2-D list of probability distributions over each time
step, with each element being a list of normalized
probabilities over vocabulary and blank.
:type probs_seq: 2-D list
:param vocabulary: Vocabulary list.
:type vocabulary: list
:return: Decoding result string.
:rtype: basestring
"""
return swig_decoders.ctc_greedy_decoder(probs_seq.tolist(), vocabulary)
def ctc_beam_search_decoder(probs_seq,
vocabulary,
beam_size,
cutoff_prob=1.0,
cutoff_top_n=40,
ext_scoring_func=None):
"""Wrapper for the CTC Beam Search Decoder.
:param probs_seq: 2-D list of probability distributions over each time
step, with each element being a list of normalized
probabilities over vocabulary and blank.
:type probs_seq: 2-D list
:param vocabulary: Vocabulary list.
:type vocabulary: list
:param beam_size: Width for beam search.
:type beam_size: int
:param cutoff_prob: Cutoff probability in pruning,
default 1.0, no pruning.
:type cutoff_prob: float
:param cutoff_top_n: Cutoff number in pruning, only top cutoff_top_n
characters with highest probs in vocabulary will be
used in beam search, default 40.
:type cutoff_top_n: int
:param ext_scoring_func: External scoring function for
partially decoded sentence, e.g. word count
or language model.
:type external_scoring_func: callable
:return: List of tuples of log probability and sentence as decoding
results, in descending order of the probability.
:rtype: list
"""
return swig_decoders.ctc_beam_search_decoder(probs_seq.tolist(), vocabulary,
beam_size, cutoff_prob,
cutoff_top_n, ext_scoring_func)
def ctc_beam_search_decoder_batch(probs_split,
vocabulary,
beam_size,
num_processes,
cutoff_prob=1.0,
cutoff_top_n=40,
ext_scoring_func=None):
"""Wrapper for the batched CTC beam search decoder.
:param probs_seq: 3-D list with each element as an instance of 2-D list
of probabilities used by ctc_beam_search_decoder().
:type probs_seq: 3-D list
:param vocabulary: Vocabulary list.
:type vocabulary: list
:param beam_size: Width for beam search.
:type beam_size: int
:param num_processes: Number of parallel processes.
:type num_processes: int
:param cutoff_prob: Cutoff probability in vocabulary pruning,
default 1.0, no pruning.
:type cutoff_prob: float
:param cutoff_top_n: Cutoff number in pruning, only top cutoff_top_n
characters with highest probs in vocabulary will be
used in beam search, default 40.
:type cutoff_top_n: int
:param num_processes: Number of parallel processes.
:type num_processes: int
:param ext_scoring_func: External scoring function for
partially decoded sentence, e.g. word count
or language model.
:type external_scoring_function: callable
:return: List of tuples of log probability and sentence as decoding
results, in descending order of the probability.
:rtype: list
"""
probs_split = [probs_seq.tolist() for probs_seq in probs_split]
return swig_decoders.ctc_beam_search_decoder_batch(
probs_split, vocabulary, beam_size, num_processes, cutoff_prob,
cutoff_top_n, ext_scoring_func)
......@@ -4,7 +4,7 @@ from __future__ import division
from __future__ import print_function
import unittest
from model_utils import decoder
from decoders import decoders_deprecated as decoder
class TestDecoders(unittest.TestCase):
......@@ -66,16 +66,14 @@ class TestDecoders(unittest.TestCase):
beam_result = decoder.ctc_beam_search_decoder(
probs_seq=self.probs_seq1,
beam_size=self.beam_size,
vocabulary=self.vocab_list,
blank_id=len(self.vocab_list))
vocabulary=self.vocab_list)
self.assertEqual(beam_result[0][1], self.beam_search_result[0])
def test_beam_search_decoder_2(self):
beam_result = decoder.ctc_beam_search_decoder(
probs_seq=self.probs_seq2,
beam_size=self.beam_size,
vocabulary=self.vocab_list,
blank_id=len(self.vocab_list))
vocabulary=self.vocab_list)
self.assertEqual(beam_result[0][1], self.beam_search_result[1])
def test_beam_search_decoder_batch(self):
......@@ -83,7 +81,6 @@ class TestDecoders(unittest.TestCase):
probs_split=[self.probs_seq1, self.probs_seq2],
beam_size=self.beam_size,
vocabulary=self.vocab_list,
blank_id=len(self.vocab_list),
num_processes=24)
self.assertEqual(beam_results[0][0][1], self.beam_search_result[0])
self.assertEqual(beam_results[1][0][1], self.beam_search_result[1])
......
......@@ -100,7 +100,7 @@ class AsrRequestHandler(SocketServer.BaseRequestHandler):
finish_time = time.time()
print("Response Time: %f, Transcript: %s" %
(finish_time - start_time, transcript))
self.request.sendall(transcript)
self.request.sendall(transcript.encode('utf-8'))
def _write_to_file(self, data):
# prepare save dir and filename
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -21,9 +21,10 @@ python -u infer.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--cutoff_top_n=40 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -30,13 +30,14 @@ python -u infer.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--cutoff_top_n=40 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
--infer_manifest='data/tiny/manifest.test-clean' \
--infer_manifest='data/librispeech/manifest.test-clean' \
--mean_std_path='models/librispeech/mean_std.npz' \
--vocab_path='models/librispeech/vocab.txt' \
--model_path='models/librispeech/params.tar.gz' \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -22,9 +22,9 @@ python -u test.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -31,13 +31,14 @@ python -u test.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--cutoff_top_n=40 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
--test_manifest='data/tiny/manifest.test-clean' \
--test_manifest='data/librispeech/manifest.test-clean' \
--mean_std_path='models/librispeech/mean_std.npz' \
--vocab_path='models/librispeech/vocab.txt' \
--model_path='models/librispeech/params.tar.gz' \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -17,6 +17,7 @@ python -u train.py \
--learning_rate=5e-4 \
--max_duration=27.0 \
--min_duration=0.0 \
--test_off=False \
--use_sortagrad=True \
--use_gru=False \
--use_gpu=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......
#! /usr/bin/bash
#! /usr/bin/env bash
# TODO: replace the model with a mandarin model
pushd ../.. > /dev/null
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -21,9 +21,9 @@ python -u infer.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -30,9 +30,9 @@ python -u infer.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -22,9 +22,9 @@ python -u test.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -31,9 +31,9 @@ python -u test.py \
--num_conv_layers=2 \
--num_rnn_layers=3 \
--rnn_layer_size=2048 \
--alpha=0.36 \
--beta=0.25 \
--cutoff_prob=0.99 \
--alpha=2.15 \
--beta=0.35 \
--cutoff_prob=1.0 \
--use_gru=False \
--use_gpu=True \
--share_rnn_weights=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......@@ -17,6 +17,7 @@ python -u train.py \
--learning_rate=1e-5 \
--max_duration=27.0 \
--min_duration=0.0 \
--test_off=False \
--use_sortagrad=True \
--use_gru=False \
--use_gpu=True \
......
#! /usr/bin/bash
#! /usr/bin/env bash
pushd ../.. > /dev/null
......
......@@ -21,9 +21,10 @@ add_arg('num_proc_bsearch', int, 12, "# of CPUs for beam search.")
add_arg('num_conv_layers', int, 2, "# of convolution layers.")
add_arg('num_rnn_layers', int, 3, "# of recurrent layers.")
add_arg('rnn_layer_size', int, 2048, "# of recurrent cells per layer.")
add_arg('alpha', float, 0.36, "Coef of LM for beam search.")
add_arg('beta', float, 0.25, "Coef of WC for beam search.")
add_arg('cutoff_prob', float, 0.99, "Cutoff probability for pruning.")
add_arg('alpha', float, 2.15, "Coef of LM for beam search.")
add_arg('beta', float, 0.35, "Coef of WC for beam search.")
add_arg('cutoff_prob', float, 1.0, "Cutoff probability for pruning.")
add_arg('cutoff_top_n', int, 40, "Cutoff number for pruning.")
add_arg('use_gru', bool, False, "Use GRUs instead of simple RNNs.")
add_arg('use_gpu', bool, True, "Use GPU or not.")
add_arg('share_rnn_weights',bool, True, "Share input-hidden weights across "
......@@ -84,6 +85,10 @@ def infer():
use_gru=args.use_gru,
pretrained_model_path=args.model_path,
share_rnn_weights=args.share_rnn_weights)
# decoders only accept string encoded in utf-8
vocab_list = [chars.encode("utf-8") for chars in data_generator.vocab_list]
result_transcripts = ds2_model.infer_batch(
infer_data=infer_data,
decoding_method=args.decoding_method,
......@@ -91,7 +96,8 @@ def infer():
beam_beta=args.beta,
beam_size=args.beam_size,
cutoff_prob=args.cutoff_prob,
vocab_list=data_generator.vocab_list,
cutoff_top_n=args.cutoff_top_n,
vocab_list=vocab_list,
language_model_path=args.lang_model_path,
num_processes=args.num_proc_bsearch)
......@@ -106,6 +112,7 @@ def infer():
print("Current error rate [%s] = %f" %
(args.error_rate_type, error_rate_func(target, result)))
ds2_model.logger.info("finish inference")
def main():
print_arguments(args)
......
......@@ -6,13 +6,18 @@ from __future__ import print_function
import sys
import os
import time
import logging
import gzip
from distutils.dir_util import mkpath
import paddle.v2 as paddle
from model_utils.lm_scorer import LmScorer
from model_utils.decoder import ctc_greedy_decoder, ctc_beam_search_decoder
from model_utils.decoder import ctc_beam_search_decoder_batch
from decoders.swig_wrapper import Scorer
from decoders.swig_wrapper import ctc_greedy_decoder
from decoders.swig_wrapper import ctc_beam_search_decoder_batch
from model_utils.network import deep_speech_v2_network
logging.basicConfig(
format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)d] %(message)s')
class DeepSpeech2Model(object):
"""DeepSpeech2Model class.
......@@ -43,6 +48,8 @@ class DeepSpeech2Model(object):
self._inferer = None
self._loss_inferer = None
self._ext_scorer = None
self.logger = logging.getLogger("")
self.logger.setLevel(level=logging.INFO)
def train(self,
train_batch_reader,
......@@ -53,7 +60,8 @@ class DeepSpeech2Model(object):
num_passes,
output_model_dir,
is_local=True,
num_iterations_print=100):
num_iterations_print=100,
test_off=False):
"""Train the model.
:param train_batch_reader: Train data reader.
......@@ -76,10 +84,12 @@ class DeepSpeech2Model(object):
:type is_local: bool
:param output_model_dir: Directory for saving the model (every pass).
:type output_model_dir: basestring
:param test_off: Turn off testing.
:type test_off: bool
"""
# prepare model output directory
if not os.path.exists(output_model_dir):
os.mkdir(output_model_dir)
mkpath(output_model_dir)
# prepare optimizer and trainer
optimizer = paddle.optimizer.Adam(
......@@ -113,14 +123,19 @@ class DeepSpeech2Model(object):
start_time = time.time()
cost_sum, cost_counter = 0.0, 0
if isinstance(event, paddle.event.EndPass):
result = trainer.test(
reader=dev_batch_reader, feeding=feeding_dict)
if test_off:
print("\n------- Time: %d sec, Pass: %d" %
(time.time() - start_time, event.pass_id))
else:
result = trainer.test(
reader=dev_batch_reader, feeding=feeding_dict)
print("\n------- Time: %d sec, Pass: %d, "
"ValidationCost: %s" %
(time.time() - start_time, event.pass_id, 0))
output_model_path = os.path.join(
output_model_dir, "params.pass-%d.tar.gz" % event.pass_id)
with gzip.open(output_model_path, 'w') as f:
self._parameters.to_tar(f)
print("\n------- Time: %d sec, Pass: %d, ValidationCost: %s" %
(time.time() - start_time, event.pass_id, result.cost))
# run train
trainer.train(
......@@ -148,8 +163,8 @@ class DeepSpeech2Model(object):
return self._loss_inferer.infer(input=infer_data)
def infer_batch(self, infer_data, decoding_method, beam_alpha, beam_beta,
beam_size, cutoff_prob, vocab_list, language_model_path,
num_processes):
beam_size, cutoff_prob, cutoff_top_n, vocab_list,
language_model_path, num_processes):
"""Model inference. Infer the transcription for a batch of speech
utterances.
......@@ -169,6 +184,10 @@ class DeepSpeech2Model(object):
:param cutoff_prob: Cutoff probability in pruning,
default 1.0, no pruning.
:type cutoff_prob: float
:param cutoff_top_n: Cutoff number in pruning, only top cutoff_top_n
characters with highest probs in vocabulary will be
used in beam search, default 40.
:type cutoff_top_n: int
:param vocab_list: List of tokens in the vocabulary, for decoding.
:type vocab_list: list
:param language_model_path: Filepath for language model.
......@@ -200,21 +219,33 @@ class DeepSpeech2Model(object):
elif decoding_method == "ctc_beam_search":
# initialize external scorer
if self._ext_scorer == None:
self._ext_scorer = LmScorer(beam_alpha, beam_beta,
language_model_path)
self._loaded_lm_path = language_model_path
self.logger.info("begin to initialize the external scorer "
"for decoding")
self._ext_scorer = Scorer(beam_alpha, beam_beta,
language_model_path, vocab_list)
lm_char_based = self._ext_scorer.is_character_based()
lm_max_order = self._ext_scorer.get_max_order()
lm_dict_size = self._ext_scorer.get_dict_size()
self.logger.info("language model: "
"is_character_based = %d," % lm_char_based +
" max_order = %d," % lm_max_order +
" dict_size = %d" % lm_dict_size)
self.logger.info("end initializing scorer. Start decoding ...")
else:
self._ext_scorer.reset_params(beam_alpha, beam_beta)
assert self._loaded_lm_path == language_model_path
# beam search decode
num_processes = min(num_processes, len(probs_split))
beam_search_results = ctc_beam_search_decoder_batch(
probs_split=probs_split,
vocabulary=vocab_list,
beam_size=beam_size,
blank_id=len(vocab_list),
num_processes=num_processes,
ext_scoring_func=self._ext_scorer,
cutoff_prob=cutoff_prob)
cutoff_prob=cutoff_prob,
cutoff_top_n=cutoff_top_n)
results = [result[0][1] for result in beam_search_results]
else:
......
#! /usr/bin/env bash
source ../../utils/utility.sh
URL='http://cloud.dlnel.org/filepub/?uuid=6c83b9d8-3255-4adf-9726-0fe0be3d0274'
MD5=28521a58552885a81cf92a1e9b133a71
TARGET=./aishell_model.tar.gz
echo "Download Aishell model ..."
download $URL $MD5 $TARGET
if [ $? -ne 0 ]; then
echo "Fail to download Aishell model!"
exit 1
fi
tar -zxvf $TARGET
exit 0
#! /usr/bin/bash
#! /usr/bin/env bash
source ../../utils/utility.sh
# TODO: add urls
URL='to-be-added'
MD5=5b4af224b26c1dc4dd972b7d32f2f52a
URL='http://cloud.dlnel.org/filepub/?uuid=17404caf-cf19-492f-9707-1fad07c19aae'
MD5=ea5024a457a91179472f6dfee60e053d
TARGET=./librispeech_model.tar.gz
......
#! /usr/bin/env bash
source ../../utils/utility.sh
URL=http://cloud.dlnel.org/filepub/?uuid=d21861e4-4ed6-45bb-ad8e-ae417a43195e
MD5="29e02312deb2e59b3c8686c7966d4fe3"
TARGET=./zh_giga.no_cna_cmn.prune01244.klm
echo "Download language model ..."
download $URL $MD5 $TARGET
if [ $? -ne 0 ]; then
echo "Fail to download the language model!"
exit 1
fi
exit 0
#! /usr/bin/bash
#! /usr/bin/env bash
source ../../utils/utility.sh
......
......@@ -2,4 +2,3 @@ scipy==0.13.1
resampy==0.1.5
SoundFile==0.9.0.post1
python_speech_features
https://github.com/luotao1/kenlm/archive/master.zip
#!/bin/bash
#! /usr/bin/env bash
# install python dependencies
if [ -f "requirements.txt" ]; then
......@@ -20,10 +20,19 @@ if [ $? != 0 ]; then
fi
tar -zxvf libsndfile-1.0.28.tar.gz
cd libsndfile-1.0.28
./configure && make && make install
./configure > /dev/null && make > /dev/null && make install > /dev/null
cd ..
rm -rf libsndfile-1.0.28
rm libsndfile-1.0.28.tar.gz
fi
# install decoders
python -c "import swig_decoders"
if [ $? != 0 ]; then
cd decoders/swig > /dev/null
sh setup.sh
cd - > /dev/null
fi
echo "Install all dependencies successfully."
......@@ -22,9 +22,10 @@ add_arg('num_proc_data', int, 12, "# of CPUs for data preprocessing.")
add_arg('num_conv_layers', int, 2, "# of convolution layers.")
add_arg('num_rnn_layers', int, 3, "# of recurrent layers.")
add_arg('rnn_layer_size', int, 2048, "# of recurrent cells per layer.")
add_arg('alpha', float, 0.36, "Coef of LM for beam search.")
add_arg('beta', float, 0.25, "Coef of WC for beam search.")
add_arg('cutoff_prob', float, 0.99, "Cutoff probability for pruning.")
add_arg('alpha', float, 2.15, "Coef of LM for beam search.")
add_arg('beta', float, 0.35, "Coef of WC for beam search.")
add_arg('cutoff_prob', float, 1.0, "Cutoff probability for pruning.")
add_arg('cutoff_top_n', int, 40, "Cutoff number for pruning.")
add_arg('use_gru', bool, False, "Use GRUs instead of simple RNNs.")
add_arg('use_gpu', bool, True, "Use GPU or not.")
add_arg('share_rnn_weights',bool, True, "Share input-hidden weights across "
......@@ -85,6 +86,9 @@ def evaluate():
pretrained_model_path=args.model_path,
share_rnn_weights=args.share_rnn_weights)
# decoders only accept string encoded in utf-8
vocab_list = [chars.encode("utf-8") for chars in data_generator.vocab_list]
error_rate_func = cer if args.error_rate_type == 'cer' else wer
error_sum, num_ins = 0.0, 0
for infer_data in batch_reader():
......@@ -95,7 +99,8 @@ def evaluate():
beam_beta=args.beta,
beam_size=args.beam_size,
cutoff_prob=args.cutoff_prob,
vocab_list=data_generator.vocab_list,
cutoff_top_n=args.cutoff_top_n,
vocab_list=vocab_list,
language_model_path=args.lang_model_path,
num_processes=args.num_proc_bsearch)
target_transcripts = [
......@@ -110,6 +115,7 @@ def evaluate():
print("Final error rate [%s] (%d/%d) = %f" %
(args.error_rate_type, num_ins, num_ins, error_sum / num_ins))
ds2_model.logger.info("finish evaluation")
def main():
print_arguments(args)
......
#! /usr/bin/env bash
BATCH_SIZE_PER_GPU=64
MIN_DURATION=6.0
MAX_DURATION=7.0
function join_by { local IFS="$1"; shift; echo "$*"; }
for NUM_GPUS in 16 8 4 2 1
do
DEVICES=$(join_by , $(seq 0 $(($NUM_GPUS-1))))
BATCH_SIZE=$(($BATCH_SIZE_PER_GPU * $NUM_GPUS))
CUDA_VISIBLE_DEVICES=$DEVICES \
python train.py \
--batch_size=$BATCH_SIZE \
--num_passes=1 \
--test_off=True \
--trainer_count=$NUM_GPUS \
--min_duration=$MIN_DURATION \
--max_duration=$MAX_DURATION > tmp.log 2>&1
if [ $? -ne 0 ];then
exit 1
fi
cat tmp.log | grep "Time" | awk '{print "GPU Num: " "'"$NUM_GPUS"'" " Time: "$3}'
rm tmp.log
done
......@@ -25,6 +25,7 @@ add_arg('num_iter_print', int, 100, "Every # iterations for printing "
add_arg('learning_rate', float, 5e-4, "Learning rate.")
add_arg('max_duration', float, 27.0, "Longest audio duration allowed.")
add_arg('min_duration', float, 0.0, "Shortest audio duration allowed.")
add_arg('test_off', bool, False, "Turn off testing.")
add_arg('use_sortagrad', bool, True, "Use SortaGrad or not.")
add_arg('use_gpu', bool, True, "Use GPU or not.")
add_arg('use_gru', bool, False, "Use GRUs instead of simple RNNs.")
......@@ -111,7 +112,8 @@ def train():
num_passes=args.num_passes,
num_iterations_print=args.num_iter_print,
output_model_dir=args.output_model_dir,
is_local=args.is_local)
is_local=args.is_local,
test_off=args.test_off)
def main():
......
......@@ -11,10 +11,13 @@ download() {
fi
fi
wget -c $URL -P `dirname "$TARGET"`
wget -c $URL -O "$TARGET"
if [ $? -ne 0 ]; then
return 1
fi
md5_result=`md5sum $TARGET | awk -F[' '] '{print $1}'`
if [ $MD5 == $md5_result ]; then
echo "Fail to download the language model!"
if [ ! $MD5 == $md5_result ]; then
return 1
fi
}
此差异已折叠。
# 深度结构化语义模型 (Deep Structured Semantic Models, DSSM)
DSSM使用DNN模型在一个连续的语义空间中学习文本低纬的表示向量,并且建模两个句子间的语义相似度。
本例演示如何使用 PaddlePaddle实现一个通用的DSSM 模型,用于建模两个字符串间的语义相似度,
模型实现支持通用的数据格式,用户替换数据便可以在真实场景中使用该模型。
# Deep Structured Semantic Models (DSSM)
Deep Structured Semantic Models (DSSM) is simple but powerful DNN based model for matching web search queries and the URL based documents. This example demonstrates how to use PaddlePaddle to implement a generic DSSM model for modeling the semantic similarity between two strings.
## 背景介绍
DSSM \[[1](##参考文献)\]是微软研究院13年提出来的经典的语义模型,用于学习两个文本之间的语义距离,
广义上模型也可以推广和适用如下场景:
## Background Introduction
DSSM \[[1](##References)]is a classic semantic model proposed by the Institute of Physics. It is used to study the semantic distance between two texts. The general implementation of DSSM is as follows.
1. CTR预估模型,衡量用户搜索词(Query)与候选网页集合(Documents)之间的相关联程度。
2. 文本相关性,衡量两个字符串间的语义相关程度。
3. 自动推荐,衡量User与被推荐的Item之间的关联程度。
1. The CTR predictor measures the degree of association between a user search query and a candidate web page.
2. Text relevance, which measures the degree of semantic correlation between two strings.
3. Automatically recommend, measure the degree of association between User and the recommended Item.
DSSM 已经发展成了一个框架,可以很自然地建模两个记录之间的距离关系,
例如对于文本相关性问题,可以用余弦相似度 (cosin similarity) 来刻画语义距离;
而对于搜索引擎的结果排序,可以在DSSM上接上Rank损失训练处一个排序模型。
## 模型简介
在原论文\[[1](#参考文献)\]中,DSSM模型用来衡量用户搜索词 Query 和文档集合 Documents 之间隐含的语义关系,模型结构如下
## Model Architecture
In the original paper \[[1](#References)] the DSSM model uses the implicit semantic relation between the user search query and the document as metric. The model structure is as follows
<p align="center">
<img src="./images/dssm.png"/><br/><br/>
图 1. DSSM 原始结构
Figure 1. DSSM In the original paper
</p>
其贯彻的思想是, **用DNN将高维特征向量转化为低纬空间的连续向量(图中红色框部分)**
**在上层用cosin similarity来衡量用户搜索词与候选文档间的语义相关性**
在最顶层损失函数的设计上,原始模型使用类似Word2Vec中负例采样的方法,
一个Query会抽取正例 $D+$ 和4个负例 $D-$ 整体上算条件概率用对数似然函数作为损失,
这也就是图 1中类似 $P(D_1|Q)$ 的结构,具体细节请参考原论文。
随着后续优化DSSM模型的结构得以简化\[[3](#参考文献)\],演变为
With the subsequent optimization of the DSSM model to simplify the structure \[[3](#References)],the model becomes
<p align="center">
<img src="./images/dssm2.png" width="600"/><br/><br/>
图 2. DSSM通用结构
Figure 2. DSSM generic structure
</p>
图中的空白方框可以用任何模型替代,比如全连接FC,卷积CNN,RNN等都可以,
该模型结构专门用于衡量两个元素(比如字符串)间的语义距离。
在现实使用中,DSSM模型会作为基础的积木,搭配上不同的损失函数来实现具体的功能,比如
- 在排序学习中,将 图 2 中结构添加 pairwise rank损失,变成一个排序模型
- 在CTR预估中,对点击与否做0,1二元分类,添加交叉熵损失变成一个分类模型
- 在需要对一个子串打分时,可以使用余弦相似度来计算相似度,变成一个回归模型
本例将尝试面向应用提供一个比较通用的解决方案,在模型任务类型上支持
The blank box in the figure can be replaced by any model, such as fully connected FC, convoluted CNN, RNN, etc. The structure is designed to measure the semantic distance between two elements (such as strings).
- 分类
- [-1, 1] 值域内的回归
- Pairwise-Rank
In practice,DSSM model serves as a basic building block, with different loss functions to achieve specific functions, such as
在生成低纬语义向量的模型结构上,本模型支持以下三种:
- In ranking system, the pairwise rank loss function.
- In the CTR estimate, instead of the binary classification on the click, use cross-entropy loss for a classification model
- In regression model, the cosine similarity is used to calculate the similarity
- FC, 多层全连接层
- CNN,卷积神经网络
- RNN,递归神经网络
## Model Implementation
At a high level, DSSM model is composed of three components: the left and right DNN, and loss function on top of them. In complex tasks, the structure of the left DNN and the light DNN can be different. In this example, we keep these two DNN structures the same. And we choose any of FC, CNN, and RNN for the DNN architecture.
## 模型实现
DSSM模型可以拆成三小块实现,分别是左边和右边的DNN,以及顶层的损失函数。
在复杂任务中,左右两边DNN的结构可以是不同的,比如在原始论文中左右分别学习Query和Document的semantic vector,
两者数据的数据不同,建议对应定制DNN的结构。
In PaddlePaddle, the loss functions are supported for any of classification, regression, and ranking. Among them, the distance between the left and right DNN is calculated by the cosine similarity. In the classification task, the predicted distribution is calculated by softmax.
本例中为了简便和通用,将左右两个DNN的结构都设为相同的,因此只有三个选项FC,CNN,RNN等。
Here we demonstrate:
在损失函数的设计方面,也支持三种,分类, 回归, 排序;
其中,在回归和排序两种损失中,左右两边的匹配程度通过余弦相似度(cossim)来计算;
在分类任务中,类别预测的分布通过softmax计算。
- How CNN, FC do text information extraction can refer to [text classification](https://github.com/PaddlePaddle/models/blob/develop/text_classification/README.md#模型详解)
- The contents of the RNN / GRU can be found in [Machine Translation](https://github.com/PaddlePaddle/book/blob/develop/08.machine_translation/README.md#gated-recurrent-unit-gru)
- For Pairwise Rank learning, please refer to [learn to rank](https://github.com/PaddlePaddle/models/blob/develop/ltr/README.md)
在其它教程中,对上述很多内容都有过详细的介绍,例如:
- 如何CNN, FC 做文本信息提取可以参考 [text classification](https://github.com/PaddlePaddle/models/blob/develop/text_classification/README.md#模型详解)
- RNN/GRU 的内容可以参考 [Machine Translation](https://github.com/PaddlePaddle/book/blob/develop/08.machine_translation/README.md#gated-recurrent-unit-gru)
- Pairwise Rank即排序学习可参考 [learn to rank](https://github.com/PaddlePaddle/models/blob/develop/ltr/README.md)
相关原理在此不再赘述,本文接下来的篇幅主要集中介绍使用PaddlePaddle实现这些结构上。
如图3,回归和分类模型的结构很相似
Figure 3 shows the general architecture for both regression and classification models.
<p align="center">
<img src="./images/dssm3.jpg"/><br/><br/>
3. DSSM for REGRESSION or CLASSIFICATION
Figure 3. DSSM for REGRESSION or CLASSIFICATION
</p>
最重要的组成部分包括词向量,图中`(1)`,`(2)`两个低纬向量的学习器(可以用RNN/CNN/FC中的任意一种实现),
最上层对应的损失函数。
而Pairwise Rank的结构会复杂一些,类似两个 图 4. 中的结构,增加了对应的损失函数:
- 模型总体思想是,用同一个source(源)为左右两个target(目标)分别打分——`(a),(b)`,学习目标是(a),(b)间的大小关系
- `(a)``(b)`类似图3中结构,用于给source和target的pair打分
- `(1)``(2)`的结构其实是共用的,都表示同一个source,图中为了表达效果展开成两个
The structure of the Pairwise Rank is more complex, as shown in Figure 4.
<p align="center">
<img src="./images/dssm2.jpg"/><br/><br/>
图 4. DSSM for Pairwise Rank
</p>
下面是各个部分具体的实现方法,所有的代码均包含在 `./network_conf.py` 中。
In below, we describe how to train DSSM model in PaddlePaddle. All the codes are included in `./network_conf.py`.
### 创建文本的词向量表
### Create a word vector table for the text
```python
def create_embedding(self, input, prefix=''):
'''
......@@ -117,10 +77,9 @@ def create_embedding(self, input, prefix=''):
return emb
```
由于输入给词向量表(embedding table)的是一个句子对应的词的ID的列表 ,因此词向量表输出的是词向量的序列。
### CNN 结构实现
Since the input (embedding table) is a list of the IDs of the words corresponding to a sentence, the word vector table outputs the sequence of word vectors.
### CNN implementation
```python
def create_cnn(self, emb, prefix=''):
'''
......@@ -151,14 +110,11 @@ def create_cnn(self, emb, prefix=''):
return conv_3, conv_4
```
CNN 接受 embedding table输出的词向量序列,通过卷积和池化操作捕捉到原始句子的关键信息,
最终输出一个语义向量(可以认为是句子向量)。
本例的实现中,分别使用了窗口长度为3和4的CNN学到的句子向量按元素求和得到最终的句子向量。
CNN accepts the word sequence of the embedding table, then process the data by convolution and pooling, and finally outputs a semantic vector.
### RNN 结构实现
### RNN implementation
RNN很适合学习变长序列的信息,使用RNN来学习句子的信息几乎是自然语言处理任务的标配。
RNN is suitable for learning variable length of the information
```python
def create_rnn(self, emb, prefix=''):
......@@ -170,7 +126,7 @@ def create_rnn(self, emb, prefix=''):
return sent_vec
```
### FC 结构实现
### FC implementation
```python
def create_fc(self, emb, prefix=''):
......@@ -188,11 +144,9 @@ def create_fc(self, emb, prefix=''):
return fc
```
在构建FC时需要首先使用`paddle.layer.pooling` 对词向量序列进行最大池化操作,将边长序列转化为一个固定维度向量,
作为整个句子的语义表达,使用最大池化能够降低句子长度对句向量表达的影响。
In the construction of FC, we use `paddle.layer.pooling` for the maximum pooling operation on the word vector sequence. Then we transform the sequence into a fixed dimensional vector.
### 多层DNN实现
在 CNN/DNN/FC提取出 semantic vector后,在上层可继续接多层FC来实现深层DNN结构。
### Multi-layer DNN implementation
```python
def create_dnn(self, sent_vec, prefix):
......@@ -215,8 +169,8 @@ def create_dnn(self, sent_vec, prefix):
return _input_layer
```
### 分类或回归实现
分类和回归的结构比较相似,因此可以用一个函数创建出来
### Classification / Regression
The structure of classification and regression is similar. Below function can be used for both tasks.
```python
def _build_classification_or_regression_model(self, is_classification):
......@@ -269,9 +223,9 @@ def _build_classification_or_regression_model(self, is_classification):
prediction, label)
return cost, prediction, label
```
### Pairwise Rank实现
Pairwise Rank复用上面的DNN结构,同一个source对两个target求相似度打分,
如果左边的target打分高,预测为1,否则预测为 0。
### Pairwise Rank
```python
def _build_rank_model(self):
......@@ -323,10 +277,10 @@ def _build_rank_model(self):
# so AUC will not used.
return cost, None, None
```
## 数据格式
`./data` 中有简单的示例数据
## Data Format
Below is a simple example for the data in `./data`
### 回归的数据格式
### Regression data format
```
# 3 fields each line:
# - source's word ids
......@@ -335,13 +289,14 @@ def _build_rank_model(self):
<ids> \t <ids> \t <float>
```
比如:
The example of this format is as follows.
```
3 6 10 \t 6 8 33 \t 0.7
6 0 \t 6 9 330 \t 0.03
```
### 分类的数据格式
### Classification data format
```
# 3 fields each line:
# - source's word ids
......@@ -350,7 +305,8 @@ def _build_rank_model(self):
<ids> \t <ids> \t <label>
```
比如:
The example of this format is as follows.
```
3 6 10 \t 6 8 33 \t 0
......@@ -358,7 +314,7 @@ def _build_rank_model(self):
```
### 排序的数据格式
### Ranking data format
```
# 4 fields each line:
# - source's word ids
......@@ -368,18 +324,17 @@ def _build_rank_model(self):
<ids> \t <ids> \t <ids> \t <label>
```
比如:
The example of this format is as follows.
```
7 2 4 \t 2 10 12 \t 9 2 7 10 23 \t 0
7 2 4 \t 10 12 \t 9 2 21 23 \t 1
```
## 执行训练
## Training
可以直接执行 `python train.py -y 0 --model_arch 0` 使用 `./data/classification` 目录里简单的数据来训练一个分类的FC模型。
We use `python train.py -y 0 --model_arch 0` with the data in `./data/classification` to train a DSSM model for classification.
其他模型结构也可以通过命令行实现定制,详细命令行参数如下
```
usage: train.py [-h] [-i TRAIN_DATA_PATH] [-t TEST_DATA_PATH]
......@@ -438,17 +393,17 @@ optional arguments:
number of batches to output model, (default: 400)
```
重要的参数描述如下
Parameter description:
- `train_data_path` 训练数据路径
- `test_data_path` 测试数据路局,可以不设置
- `source_dic_path` 源字典字典路径
- `target_dic_path`标字典路径
- `model_type` 模型的损失函数的类型,分类0,排序1,回归2
- `model_arch` 模型结构,FC 0, CNN 1, RNN 2
- `dnn_dims` 模型各层的维度设置,默认为 `256,128,64,32`,即模型有4层,各层维度如上设置
- `train_data_path` Training data path
- `test_data_path` Test data path, optional
- `source_dic_path` Source dictionary path
- `target_dic_path`Target dictionary path
- `model_type` The type of loss function of the model: classification 0, sort 1, regression 2
- `model_arch` Model structure: FC 0,CNN 1, RNN 2
- `dnn_dims` The dimension of each layer of the model is set, the default is `256,128,64,32`,with 4 layers.
## 用训练好的模型预测
## To predict using the trained model
```
usage: infer.py [-h] --model_path MODEL_PATH -i DATA_PATH -o
PREDICTION_OUTPUT_PATH -y MODEL_TYPE [-s SOURCE_DIC_PATH]
......@@ -490,12 +445,12 @@ optional arguments:
number of categories for classification task.
```
部分参数可以参考 `train.py`,重要参数解释如下
Important parameters are
- `data_path` 需要预测的数据路径
- `prediction_output_path` 预测的输出路径
- `data_path` Path for the data to predict
- `prediction_output_path` Prediction output path
## 参考文献
## References
1. Huang P S, He X, Gao J, et al. Learning deep structured semantic models for web search using clickthrough data[C]//Proceedings of the 22nd ACM international conference on Conference on information & knowledge management. ACM, 2013: 2333-2338.
2. [Microsoft Learning to Rank Datasets](https://www.microsoft.com/en-us/research/project/mslr/)
......
此差异已折叠。
# 神经网络机器翻译模型
## 背景介绍
机器翻译利用计算机将源语言转换成目标语言的同义表达,是自然语言处理中重要的研究方向,有着广泛的应用需求,其实现方式也经历了不断地演化。传统机器翻译方法主要基于规则或统计模型,需要人为地指定翻译规则或设计语言特征,效果依赖于人对源语言与目标语言的理解程度。近些年来,深度学习的提出与迅速发展使得特征的自动学习成为可能。深度学习首先在图像识别和语音识别中取得成功,进而在机器翻译等自然语言处理领域中掀起了研究热潮。机器翻译中的深度学习模型直接学习源语言到目标语言的映射,大为减少了学习过程中人的介入,同时显著地提高了翻译质量。本例介绍在PaddlePaddle中如何利用循环神经网络(Recurrent Neural Network, RNN)构建一个端到端(End-to-End)的神经网络机器翻译(Neural Machine Translation, NMT)模型。
## 模型概览
基于 RNN 的神经网络机器翻译模型遵循编码器-解码器结构,其中的编码器和解码器均是一个循环神经网络。将构成编码器和解码器的两个 RNN 沿时间步展开,得到如下的模型结构图:
<p align="center"><img src="images/encoder-decoder.png" width = "90%" align="center"/><br/>图 1. 编码器-解码器框架 </p>
神经机器翻译模型的输入输出可以是字符,也可以是词或者短语。不失一般性,本例以基于词的模型为例说明编码器/解码器的工作机制:
- **编码器**:将源语言句子编码成一个向量,作为解码器的输入。解码器的原始输入是表示词的 `id` 序列 $w = {w_1, w_2, ..., w_T}$,用独热(One-hot)码表示。为了对输入进行降维,同时建立词语之间的语义关联,模型为热独码表示的单词学习一个词嵌入(Word Embedding)表示,也就是常说的词向量,关于词向量的详细介绍请参考 PaddleBook 的[词向量](https://github.com/PaddlePaddle/book/blob/develop/04.word2vec/README.cn.md)一章。最后 RNN 单元逐个词地处理输入,得到完整句子的编码向量。
- **解码器**:接受编码器的输入,逐个词地解码出目标语言序列 $u = {u_1, u_2, ..., u_{T'}}$。每个时间步,RNN 单元输出一个隐藏向量,之后经 `Softmax` 归一化计算出下一个目标词的条件概率,即 $P(u_i | w, u_1, u_2, ..., u_{t-1})$。因此,给定输入 $w$,其对应的翻译结果为 $u$ 的概率则为
$$ P(u_1,u_2,...,u_{T'} | w) = \prod_{t=1}^{t={T'}}p(u_t|w, u_1, u_2, u_{t-1})$$
以中文到英文的翻译为例,源语言是中文,目标语言是英文。下面是一句源语言分词后的句子
```
祝愿 祖国 繁荣 昌盛
```
对应的目标语言英文翻译结果为:
```
Wish motherland rich and powerful
```
在预处理阶段,准备源语言与目标语言互译的平行语料数据,并分别构建源语言和目标语言的词典;在训练阶段,用这样成对的平行语料训练模型;在模型测试阶段,输入中文句子,模型自动生成对应的英语翻译,然后将生成结果与标准翻译对比进行评估。在机器翻译领域,BLEU 是最流行的自动评估指标之一。
### RNN 单元
RNN 的原始结构用一个向量来存储隐状态,然而这种结构的 RNN 在训练时容易发生梯度弥散(gradient vanishing),对于长时间的依赖关系难以建模。因此人们对 RNN 单元进行了改进,提出了 LSTM\[[1](#参考文献)] 和 GRU\[[2](#参考文献)],这两种单元以门来控制应该记住的和遗忘的信息,较好地解决了序列数据的长时依赖问题。以本例所用的 GRU 为例,其基本结构如下:
<p align="center">
<img src="images/gru.png" width = "90%" align="center"/><br/>
图 2. GRU 单元
</p>
可以看到除了隐含状态以外,GRU 内部还包含了两个门:更新门(Update Gate)、重置门(Reset Gate)。在每一个时间步,门限和隐状态的更新由图 2 右侧的公式决定。这两个门限决定了状态以何种方式更新。
### 双向编码器
在上述的基本模型中,编码器在顺序处理输入句子序列时,当前时刻的状态只包含了历史输入信息,而没有未来时刻的序列信息。而对于序列建模,未来时刻的上下文同样包含了重要的信息。可以使用如图 3 所示的这种双向编码器来同时获取当前时刻输入的上下文:
<p align="center">
<img src="images/bidirectional-encoder.png" width = "90%" align="center"/><br/>
图 3. 双向编码器结构示意图
</p>
图 3 所示的双向编码器\[[3](#参考文献)\]由两个独立的 RNN 构成,分别从前向和后向对输入序列进行编码,然后将两个 RNN 的输出合并在一起,作为最终的编码输出。
在 PaddlePaddle 中,双向编码器可以很方便地调用相关 APIs 实现:
```python
src_word_id = paddle.layer.data(
name='source_language_word',
type=paddle.data_type.integer_value_sequence(source_dict_dim))
# source embedding
src_embedding = paddle.layer.embedding(
input=src_word_id, size=word_vector_dim)
# bidirectional GRU as encoder
encoded_vector = paddle.networks.bidirectional_gru(
input=src_embedding,
size=encoder_size,
fwd_act=paddle.activation.Tanh(),
fwd_gate_act=paddle.activation.Sigmoid(),
bwd_act=paddle.activation.Tanh(),
bwd_gate_act=paddle.activation.Sigmoid(),
return_seq=True)
```
### 柱搜索(Beam Search) 算法
训练完成后的生成阶段,模型根据源语言输入,解码生成对应的目标语言翻译结果。解码时,一个直接的方式是取每一步条件概率最大的词,作为当前时刻的输出。但局部最优并不一定能得到全局最优,即这种做法并不能保证最后得到的完整句子出现的概率最大。如果对解的全空间进行搜索,其代价又过大。为了解决这个问题,通常采用柱搜索(Beam Search)算法。柱搜索是一种启发式的图搜索算法,用一个参数 $k$ 控制搜索宽度,其要点如下:
**1**. 在解码的过程中,始终维护 $k$ 个已解码出的子序列;
**2**. 在中间时刻 $t$, 对于 $k$ 个子序列中的每个序列,计算下一个词出现的概率并取概率最大的前 $k$ 个词,组合得到 $k^2$ 个新子序列;
**3**. 取 **2** 中这些组合序列中概率最大的前 $k$ 个以更新原来的子序列;
**4**. 不断迭代下去,直至得到 $k$ 个完整的句子,作为翻译结果的候选。
关于柱搜索的更多介绍,可以参考 PaddleBook 中[机器翻译](https://github.com/PaddlePaddle/book/blob/develop/08.machine_translation/README.cn.md)一章中[柱搜索](https://github.com/PaddlePaddle/book/blob/develop/08.machine_translation/README.cn.md#柱搜索算法)一节。
### 无注意力机制的解码器
- PaddleBook中[机器翻译](https://github.com/PaddlePaddle/book/blob/develop/08.machine_translation/README.cn.md)的相关章节中,已介绍了带注意力机制(Attention Mechanism)的 Encoder-Decoder 结构,本例介绍的则是不带注意力机制的 Encoder-Decoder 结构。关于注意力机制,读者可进一步参考 PaddleBook 和参考文献\[[3](#参考文献)]。
对于流行的RNN单元,PaddlePaddle 已有很好的实现均可直接调用。如果希望在 RNN 每一个时间步实现某些自定义操作,可使用 PaddlePaddle 中的`recurrent_layer_group`。首先,自定义单步逻辑函数,再利用函数 `recurrent_group()` 循环调用单步逻辑函数处理整个序列。本例中的无注意力机制的解码器便是使用`recurrent_layer_group`来实现,其中,单步逻辑函数`gru_decoder_without_attention()`相关代码如下:
```python
# the initialization state for decoder GRU
encoder_last = paddle.layer.last_seq(input=encoded_vector)
encoder_last_projected = paddle.layer.fc(
size=decoder_size, act=paddle.activation.Tanh(), input=encoder_last)
# the step function for decoder GRU
def gru_decoder_without_attention(enc_vec, current_word):
'''
Step function for gru decoder
:param enc_vec: encoded vector of source language
:type enc_vec: layer object
:param current_word: current input of decoder
:type current_word: layer object
'''
decoder_mem = paddle.layer.memory(
name="gru_decoder",
size=decoder_size,
boot_layer=encoder_last_projected)
context = paddle.layer.last_seq(input=enc_vec)
decoder_inputs = paddle.layer.fc(
size=decoder_size * 3, input=[context, current_word])
gru_step = paddle.layer.gru_step(
name="gru_decoder",
act=paddle.activation.Tanh(),
gate_act=paddle.activation.Sigmoid(),
input=decoder_inputs,
output_mem=decoder_mem,
size=decoder_size)
out = paddle.layer.fc(
size=target_dict_dim,
bias_attr=True,
act=paddle.activation.Softmax(),
input=gru_step)
return out
```
在模型训练和测试阶段,解码器的行为有很大的不同:
- **训练阶段**:目标翻译结果的词向量`trg_embedding`作为参数传递给单步逻辑`gru_decoder_without_attention()`,函数`recurrent_group()`循环调用单步逻辑执行,最后计算目标翻译与实际解码的差异cost并返回;
- **测试阶段**:解码器根据最后一个生成的词预测下一个词,`GeneratedInput()`自动取出模型预测出的概率最高的$k$个词的词向量传递给单步逻辑,`beam_search()`函数调用单步逻辑函数`gru_decoder_without_attention()`完成柱搜索并作为结果返回。
训练和生成的逻辑分别实现在如下的`if-else`条件分支中:
```python
group_input1 = paddle.layer.StaticInput(input=encoded_vector)
group_inputs = [group_input1]
decoder_group_name = "decoder_group"
if is_generating:
trg_embedding = paddle.layer.GeneratedInput(
size=target_dict_dim,
embedding_name="_target_language_embedding",
embedding_size=word_vector_dim)
group_inputs.append(trg_embedding)
beam_gen = paddle.layer.beam_search(
name=decoder_group_name,
step=gru_decoder_without_attention,
input=group_inputs,
bos_id=0,
eos_id=1,
beam_size=beam_size,
max_length=max_length)
return beam_gen
else:
trg_embedding = paddle.layer.embedding(
input=paddle.layer.data(
name="target_language_word",
type=paddle.data_type.integer_value_sequence(target_dict_dim)),
size=word_vector_dim,
param_attr=paddle.attr.ParamAttr(name="_target_language_embedding"))
group_inputs.append(trg_embedding)
decoder = paddle.layer.recurrent_group(
name=decoder_group_name,
step=gru_decoder_without_attention,
input=group_inputs)
lbl = paddle.layer.data(
name="target_language_next_word",
type=paddle.data_type.integer_value_sequence(target_dict_dim))
cost = paddle.layer.classification_cost(input=decoder, label=lbl)
return cost
```
## 数据准备
本例所用到的数据来自[WMT14](http://www-lium.univ-lemans.fr/~schwenk/cslm_joint_paper/),该数据集是法文到英文互译的平行语料。用[bitexts](http://www-lium.univ-lemans.fr/~schwenk/cslm_joint_paper/data/bitexts.tgz)作为训练数据,[dev+test data](http://www-lium.univ-lemans.fr/~schwenk/cslm_joint_paper/data/dev+test.tgz)作为验证与测试数据。在PaddlePaddle中已经封装好了该数据集的读取接口,在首次运行的时候,程序会自动完成下载,用户无需手动完成相关的数据准备。
## 模型的训练与测试
### 模型训练
启动模型训练的十分简单,只需在命令行窗口中执行`python train.py`。模型训练阶段 `train.py` 脚本中的 `train()` 函数依次完成了如下的逻辑:
**a) 由网络定义,解析网络结构,初始化模型参数**
```python
# define the network topolgy.
cost = seq2seq_net(source_dict_dim, target_dict_dim)
parameters = paddle.parameters.create(cost)
```
**b) 设定训练过程中的优化策略、定义训练数据读取 `reader`**
```python
# define optimization method
optimizer = paddle.optimizer.RMSProp(
learning_rate=1e-3,
gradient_clipping_threshold=10.0,
regularization=paddle.optimizer.L2Regularization(rate=8e-4))
# define the trainer instance
trainer = paddle.trainer.SGD(
cost=cost, parameters=parameters, update_equation=optimizer)
# define data reader
wmt14_reader = paddle.batch(
paddle.reader.shuffle(
paddle.dataset.wmt14.train(source_dict_dim), buf_size=8192),
batch_size=55)
```
**c) 定义事件句柄,打印训练中间结果、保存模型快照**
```python
# define the event_handler callback
def event_handler(event):
if isinstance(event, paddle.event.EndIteration):
if not event.batch_id % 100 and event.batch_id:
with gzip.open(
os.path.join(save_path,
"nmt_without_att_%05d_batch_%05d.tar.gz" %
event.pass_id, event.batch_id), "w") as f:
parameters.to_tar(f)
if event.batch_id and not event.batch_id % 10:
logger.info("Pass %d, Batch %d, Cost %f, %s" % (
event.pass_id, event.batch_id, event.cost, event.metrics))
```
**d) 开始训练**
```python
# start training
trainer.train(
reader=wmt14_reader, event_handler=event_handler, num_passes=2)
```
输出样例为
```text
Pass 0, Batch 0, Cost 267.674663, {'classification_error_evaluator': 1.0}
.........
Pass 0, Batch 10, Cost 172.892294, {'classification_error_evaluator': 0.953895092010498}
.........
Pass 0, Batch 20, Cost 177.989329, {'classification_error_evaluator': 0.9052488207817078}
.........
Pass 0, Batch 30, Cost 153.633665, {'classification_error_evaluator': 0.8643803596496582}
.........
Pass 0, Batch 40, Cost 168.170543, {'classification_error_evaluator': 0.8348183631896973}
```
### 生成翻译结果
利用训练好的模型生成翻译文本也十分简单。
1. 首先请修改`generate.py`脚本中`main`中传递给`generate`函数的参数,以选择使用哪一个保存的模型来生成。默认参数如下所示:
```python
generate(
source_dict_dim=30000,
target_dict_dim=30000,
batch_size=20,
beam_size=3,
model_path="models/nmt_without_att_params_batch_00100.tar.gz")
```
2. 在终端执行命令 `python generate.py`,脚本中的`generate()`执行了依次如下逻辑:
**a) 加载测试样本**
```python
# load data samples for generation
gen_creator = paddle.dataset.wmt14.gen(source_dict_dim)
gen_data = []
for item in gen_creator():
gen_data.append((item[0], ))
```
**b) 初始化模型,执行`infer()`为每个输入样本生成`beam search`的翻译结果**
```python
beam_gen = seq2seq_net(source_dict_dim, target_dict_dim, True)
with gzip.open(init_models_path) as f:
parameters = paddle.parameters.Parameters.from_tar(f)
# prob is the prediction probabilities, and id is the prediction word.
beam_result = paddle.infer(
output_layer=beam_gen,
parameters=parameters,
input=gen_data,
field=['prob', 'id'])
```
**c) 加载源语言和目标语言词典,将`id`序列表示的句子转化成原语言并输出结果**
```python
beam_result = inferer.infer(input=test_batch, field=["prob", "id"])
gen_sen_idx = np.where(beam_result[1] == -1)[0]
assert len(gen_sen_idx) == len(test_batch) * beam_size
start_pos, end_pos = 1, 0
for i, sample in enumerate(test_batch):
print(" ".join([
src_dict[w] for w in sample[0][1:-1]
])) # skip the start and ending mark when print the source sentence
for j in xrange(beam_size):
end_pos = gen_sen_idx[i * beam_size + j]
print("%.4f\t%s" % (beam_result[0][i][j], " ".join(
trg_dict[w] for w in beam_result[1][start_pos:end_pos])))
start_pos = end_pos + 2
print("\n")
```
设置beam search的宽度为3,输入为一个法文句子,则自动为测试数据生成对应的翻译结果,输出格式如下:
```text
Elles connaissent leur entreprise mieux que personne .
-3.754819 They know their business better than anyone . <e>
-4.445528 They know their businesses better than anyone . <e>
-5.026885 They know their business better than anybody . <e>
```
- 第一行为输入的源语言句子。
- 第二 ~ beam_size + 1 行是柱搜索生成的 `beam_size` 条翻译结果
- 相同行的输出以“\t”分隔为两列,第一列是句子的log 概率,第二列是翻译结果的文本。
- 符号`<s>` 表示句子的开始,符号`<e>`表示一个句子的结束,如果出现了在词典中未包含的词,则用符号`<unk>`替代。
至此,我们在 PaddlePaddle 上实现了一个初步的机器翻译模型。我们可以看到,PaddlePaddle 提供了灵活丰富的API供大家选择和使用,使得我们能够很方便完成各种复杂网络的配置。机器翻译本身也是个快速发展的领域,各种新方法新思想在不断涌现。在学习完本例后,读者若有兴趣和余力,可基于 PaddlePaddle 平台实现更为复杂、性能更优的机器翻译模型。
## 参考文献
[1] Sutskever I, Vinyals O, Le Q V. [Sequence to Sequence Learning with Neural Networks](https://arxiv.org/abs/1409.3215)[J]. 2014, 4:3104-3112.
[2]Cho K, Van Merriënboer B, Gulcehre C, et al. [Learning phrase representations using RNN encoder-decoder for statistical machine translation](http://www.aclweb.org/anthology/D/D14/D14-1179.pdf)[C]. Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing (EMNLP), 2014: 1724-1734.
[3] Bahdanau D, Cho K, Bengio Y. [Neural machine translation by jointly learning to align and translate](https://arxiv.org/abs/1409.0473)[C]. Proceedings of ICLR 2015, 2015
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