diff --git a/word2vec/.gitignore b/word2vec/.gitignore new file mode 100644 index 0000000000000000000000000000000000000000..a620e0279c310d213d4e6d8e99e666962c11e352 --- /dev/null +++ b/word2vec/.gitignore @@ -0,0 +1,3 @@ +data/train.list +data/test.list +data/simple-examples* diff --git a/word2vec/README.md b/word2vec/README.md index 56bab099286c196640b7150ee424e23f26d836d6..f9cb6ba95476e7725710cbe0835a40c030789fdc 100644 --- a/word2vec/README.md +++ b/word2vec/README.md @@ -1 +1,461 @@ -TODO: Base on [this tutorial](https://github.com/PaddlePaddle/Paddle/blob/develop/doc/tutorials/embedding_model/index_en.md). +# 词向量 + +## 背景介绍 + +本章我们介绍词的向量表征,也称为word embedding。词向量是自然语言处理中常见的一个操作,是搜索引擎、广告系统、推荐系统等互联网服务背后常见的基础技术。 + +在这些互联网服务里,我们经常要比较两个词或者两段文本之间的相关性。为了做这样的比较,我们往往先要把词表示成计算机适合处理的方式。最自然的方式恐怕莫过于向量空间模型(vector space model)。 +在这种方式里,每个词被表示成一个实数向量(one-hot vector),其长度为字典大小,每个维度对应一个字典里的每个词,除了这个词对应维度上的值是1,其他元素都是0。 + +One-hot vector虽然自然,但是用处有限。比如,在互联网广告系统里,如果用户输入的query是“母亲节”,而有一个广告的关键词是“康乃馨”。虽然按照常理,我们知道这两个词之间是有联系的——母亲节通常应该送给母亲一束康乃馨;但是这两个词对应的one-hot vectors之间的距离度量,无论是欧氏距离还是余弦相似度(cosine similarity),由于其向量正交,都认为这两个词毫无相关性。 得出这种与我们相悖的结论的根本原因是:每个词本身的信息量都太小。所以,仅仅给定两个词,不足以让我们准确判别它们是否相关。要想精确计算相关性,我们还需要更多的信息——从大量数据里通过机器学习方法归纳出来的知识。 + +在机器学习领域里,各种“知识”被各种模型表示,词向量模型(word embedding model)就是其中的一类。通过词向量模型可将一个 one-hot vector映射到一个维度更低的实数向量(embedding vector),如$embedding(母亲节) = [0.3, 4.2, -1.5, ...], embedding(康乃馨) = [0.2, 5.6, -2.3, ...]$。在这个映射到的实数向量表示中,希望两个语义(或用法)上相似的词对应的词向量“更像”,这样如“母亲节”和“康乃馨”的对应词向量的余弦相似度就不再为零了。 + +词向量模型可以是概率模型、共生矩阵(co-occurrence matrix)模型或神经元网络模型。在用神经网络求词向量之前,传统做法是统计一个词语的共生矩阵$X$。$X$是一个$|V| \times |V|$ 大小的矩阵,$X_{ij}$表示在所有语料中,词汇表`V`(vocabulary)中第i个词和第j个词同时出现的词数,$|V|$为词汇表的大小。对$X$做矩阵分解(如奇异值分解,Singular Value Decomposition \[[5](#参考文献)\]),得到的$U$即视为所有词的词向量: + +$$X = USV^T$$ + +但这样的传统做法有很多问题:
+1) 由于很多词没有出现,导致矩阵极其稀疏,因此需要对词频做额外处理来达到好的矩阵分解效果;
+2) 矩阵非常大,维度太高(通常达到$10^6*10^6$的数量级);
+3) 需要手动去掉停用词(如although, a,...),不然这些频繁出现的词也会影响矩阵分解的效果。 + + +基于神经网络的模型不需要计算存储一个在全语料上统计的大表,而是通过学习语义信息得到词向量,因此能很好地解决以上问题。在本章里,我们将展示基于神经网络训练词向量的细节,以及如何用PaddlePaddle训练一个词向量模型。 + + +## 效果展示 + +本章中,当词向量训练好后,我们可以用数据可视化算法t-SNE\[[4](#参考文献)\]画出词语特征在二维上的投影(如下图所示)。从图中可以看出,语义相关的词语(如a, the, these; big, huge)在投影上距离很近,语意无关的词(如say, business; decision, japan)在投影上的距离很远。 + +

+
+ 图1. 词向量的二维投影 +

+ +另一方面,我们知道两个向量的余弦值在$[-1,1]$的区间内:两个完全相同的向量余弦值为1, 两个相互垂直的向量之间余弦值为0,两个方向完全相反的向量余弦值为-1,即相关性和余弦值大小成正比。因此我们还可以计算两个词向量的余弦相似度: +``` +similarity: 0.899180685161 +please input two words: big huge + +please input two words: from company +similarity: -0.0997506977351 +``` + +以上结果可以通过运行`calculate_dis.py`, 加载字典里的单词和对应训练特征结果得到,我们将在[应用模型](#应用模型)中详细描述用法。 + + +## 模型概览 + +在这里我们介绍三个训练词向量的模型:N-gram模型,CBOW模型和Skip-gram模型,它们的中心思想都是通过上下文得到一个词出现的概率。对于N-gram模型,我们会先介绍语言模型的概念,并在之后的[训练模型](#训练模型)中,带大家用PaddlePaddle实现它。而后两个模型,是近年来最有名的神经元词向量模型,由 Tomas Mikolov 在Google 研发\[[3](#参考文献)\],虽然它们很浅很简单,但训练效果很好。 + +### 语言模型 + +在介绍词向量模型之前,我们先来引入一个概念:语言模型。 +语言模型旨在为语句的联合概率函数$P(w_1, ..., w_T)$建模, 其中$w_i$表示句子中的第i个词。语言模型的目标是,希望模型对有意义的句子赋予大概率,对没意义的句子赋予小概率。 +这样的模型可以应用于很多领域,如机器翻译、语音识别、信息检索、词性标注、手写识别等,它们都希望能得到一个连续序列的概率。 以信息检索为例,当你在搜索“how long is a football bame”时(bame是一个医学名词),搜索引擎会提示你是否希望搜索"how long is a football game", 这是因为根据语言模型计算出“how long is a football bame”的概率很低,而与bame近似的,可能引起错误的词中,game会使该句生成的概率最大。 + +对语言模型的目标概率$P(w_1, ..., w_T)$,如果假设文本中每个词都是相互独立的,则整句话的联合概率可以表示为其中所有词语条件概率的乘积,即: + +$$P(w_1, ..., w_T) = \prod_{t=1}^TP(w_t)$$ + +然而我们知道语句中的每个词出现的概率都与其前面的词紧密相关, 所以实际上通常用条件概率表示语言模型: + +$$P(w_1, ..., w_T) = \prod_{t=1}^TP(w_t | w_1, ... , w_{t-1})$$ + + + +### N-gram neural model + +在计算语言学中,n-gram是一种重要的文本表示方法,表示一个文本中连续的n个项。基于具体的应用场景,每一项可以是一个字母、单词或者音节。 n-gram模型也是统计语言模型中的一种重要方法,用n-gram训练语言模型时,一般用每个n-gram的历史n-1个词语组成的内容来预测第n个词。 + +Yoshua Bengio等科学家就于2003年在著名论文 Neural Probabilistic Language Models \[[1](#参考文献)\] 中介绍如何学习一个神经元网络表示的词向量模型。文中的神经概率语言模型(Neural Network Language Model,NNLM)通过一个线性映射和一个非线性隐层连接,同时学习了语言模型和词向量,即通过学习大量语料得到词语的向量表达,通过这些向量得到整个句子的概率。用这种方法学习语言模型可以克服维度灾难(curse of dimensionality),即训练和测试数据不同导致的模型不准。注意:由于“神经概率语言模型”说法较为泛泛,我们在这里不用其NNLM的本名,考虑到其具体做法,本文中称该模型为N-gram neural model。 + +我们在上文中已经讲到用条件概率建模语言模型,即一句话中第$t$个词的概率和该句话的前$t-1$个词相关。可实际上越远的词语其实对该词的影响越小,那么如果考虑一个n-gram, 每个词都只受其前面`n-1`个词的影响,则有: + +$$P(w_1, ..., w_T) = \prod_{t=n}^TP(w_t|w_{t-1}, w_{t-2}, ..., w_{t-n+1})$$ + +给定一些真实语料,这些语料中都是有意义的句子,N-gram模型的优化目标则是最大化目标函数: + +$$\frac{1}{T}\sum_t f(w_t, w_{t-1}, ..., w_{t-n+1};\theta) + R(\theta)$$ + +其中$f(w_t, w_{t-1}, ..., w_{t-n+1})$表示根据历史n-1个词得到当前词$w_t$的条件概率,$R(\theta)$表示参数正则项。 +

+
+ 图2. N-gram神经网络模型 +

+ +图2展示了N-gram神经网络模型,从下往上看,该模型分为以下几个部分: + - 对于每个样本,模型输入$w_{t-n+1},...w_{t-1}$, 输出句子第t个词为字典中`|V|`个词的概率。 + + 每个输入词$w_{t-n+1},...w_{t-1}$首先通过映射矩阵映射到词向量$C(w_{t-n+1}),...C(w_{t-1})$。 + + - 然后所有词语的词向量连接成一个大向量,并经过一个非线性映射得到历史词语的隐层表示: + + $$g=Utanh(\theta^Tx + b_1) + Wx + b_2$$ + + 其中,$x$为所有词语的词向量连接成的大向量,表示文本历史特征;$\theta$、$U$、$b_1$、$b_2$和$W$分别为词向量层到隐层连接的参数。$g$表示未经归一化的所有输出单词概率,$g_i$表示未经归一化的字典中第$i$个单词的输出概率。 + + - 根据softmax的定义,通过归一化$g_i$, 生成目标词$w_t$的概率为: + + $$P(w_t | w_1, ..., w_{t-n+1}) = \frac{e^{g_{w_t}}}{\sum_i^{|V|} e^{g_i}}$$ + + - 整个网络的损失值(cost)为多类分类交叉熵,用公式表示为 + + $$J(\theta) = -\sum_{i=1}^N\sum_{c=1}^{|V|}y_k^{i}log(softmax(g_k^i))$$ + + 其中$y_k^i$表示第$i$个样本第$k$类的真实标签(0或1),$softmax(g_k^i)$表示第i个样本第k类softmax输出的概率。 + + + +### Continuous Bag-of-Words model(CBOW) + +CBOW模型通过一个词的上下文(各N个词)预测当前词。当N=2时,模型如下图所示: +

+
+ 图3. CBOW模型 +

+ +具体来说,不考虑上下文的词语输入顺序,CBOW是用上下文词语的词向量的均值来预测当前词。即: + +$$context = \frac{x_{t-1} + x_{t-2} + x_{t+1} + x_{t+2}}{4}$$ + +其中$x_t$为第$t$个词的词向量,分类分数(score)向量 $z=U*context$,最终的分类$y$采用softmax,损失函数采用多类分类交叉熵。 + +### Skip-gram model + +CBOW的好处是对上下文词语的分布在词向量上进行了平滑,去掉了噪声,因此在小数据集上很有效。而Skip-gram的方法中,用一个词预测其上下文,得到了当前词上下文的很多样本,因此可用于更大的数据集。 +

+
+ 图4. Skip-gram模型 +

+如上图所示,Skip-gram模型的具体做法是,将一个词的词向量映射到$2n$个词的词向量($2n$表示当前输入词的前后各$n$个词),然后分别通过softmax得到这$2n$个词的分类损失值之和。 + + + +## 数据准备 + +### 数据介绍与下载 + +本教程使用Penn Tree Bank (PTB)数据集。PTB数据集较小,训练速度快,应用于Mikolov的公开语言模型训练工具\[[2](#参考文献)\]中。其统计情况如下: + +

+ + + + + + + + + + + + + + + + +
训练数据验证数据测试数据
ptb.train.txtptb.valid.txtptb.test.txt
42068句3370句3761句
+

+ +执行以下命令,可下载该数据集,并分别将训练数据和验证数据输入`train.list`和`test.list`文件中,供PaddlePaddle训练时使用。 + +```bash +./data/getdata.sh +``` + + +### 提供数据给PaddlePaddle + +1. 使用initializer函数进行dataprovider的初始化,包括字典的建立(build_dict函数中)和PaddlePaddle输入字段的格式定义。注意:这里N为n-gram模型中的`n`, 本章代码中,定义$N=5$, 表示在PaddlePaddle训练时,每条数据的前4个词用来预测第5个词。大家也可以根据自己的数据和需求自行调整N,但调整的同时要在模型配置文件中加入/减少相应输入字段。 + + ```python + from paddle.trainer.PyDataProvider2 import * + import collections + import logging + import pdb + + logging.basicConfig( + format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)s] %(message)s', ) + logger = logging.getLogger('paddle') + logger.setLevel(logging.INFO) + + N = 5 # Ngram + cutoff = 50 # select words with frequency > cutoff to dictionary + def build_dict(ftrain, fdict): + sentences = [] + with open(ftrain) as fin: + for line in fin: + line = [''] + line.strip().split() + [''] + sentences += line + wordfreq = collections.Counter(sentences) + wordfreq = filter(lambda x: x[1] > cutoff, wordfreq.items()) + dictionary = sorted(wordfreq, key = lambda x: (-x[1], x[0])) + words, _ = list(zip(*dictionary)) + for word in words: + print >> fdict, word + word_idx = dict(zip(words, xrange(len(words)))) + logger.info("Dictionary size=%s" %len(words)) + return word_idx + + def initializer(settings, srcText, dictfile, **xargs): + with open(dictfile, 'w') as fdict: + settings.dicts = build_dict(srcText, fdict) + input_types = [] + for i in xrange(N): + input_types.append(integer_value(len(settings.dicts))) + settings.input_types = input_types + ``` + +2. 使用process函数中将数据逐一提供给PaddlePaddle。具体来说,将每句话前面补上N-1个开始符号 ``, 末尾补上一个结束符号 ``,然后以N为窗口大小,从头到尾每次向右滑动窗口并生成一条数据。 + + ```python + @provider(init_hook=initializer) + def process(settings, filename): + UNKID = settings.dicts[''] + with open(filename) as fin: + for line in fin: + line = ['']*(N-1) + line.strip().split() + [''] + line = [settings.dicts.get(w, UNKID) for w in line] + for i in range(N, len(line) + 1): + yield line[i-N: i] + ``` + + 如"I have a dream" 一句提供了5条数据: + + > ` I `
+ > ` I have`
+ > ` I have a `
+ > ` I have a dream`
+ > `I have a dream `
+ + + +## 模型配置说明 + +### 数据定义 + +通过`define_py_data_sources2`函数从dataprovider中读入数据,其中args指定了训练文本(srcText)和词汇表(dictfile)。 + +```python +from paddle.trainer_config_helpers import * +import math + +args = {'srcText': 'data/simple-examples/data/ptb.train.txt', + 'dictfile': 'data/vocabulary.txt'} + +define_py_data_sources2( + train_list="data/train.list", + test_list="data/test.list", + module="dataprovider", + obj="process", + args=args) +``` + +### 算法配置 + +在这里,我们指定了模型的训练参数, L2正则项系数、学习率和batch size。 + +```python +settings( + batch_size=100, regularization=L2Regularization(8e-4), learning_rate=3e-3) +``` + +### 模型结构 + +本配置的模型结构如下图所示: + +

+
+ 图5. 模型配置中的N-gram神经网络模型 +

+ +1. 定义参数维度和和数据输入。 + + ```python + dictsize = 1953 # 字典大小 + embsize = 32 # 词向量维度 + hiddensize = 256 # 隐层维度 + + firstword = data_layer(name = "firstw", size = dictsize) + secondword = data_layer(name = "secondw", size = dictsize) + thirdword = data_layer(name = "thirdw", size = dictsize) + fourthword = data_layer(name = "fourthw", size = dictsize) + nextword = data_layer(name = "fifthw", size = dictsize) + ``` + +2. 将$w_t$之前的$n-1$个词 $w_{t-n+1},...w_{t-1}$,通过$|V|\times D$的矩阵映射到D维词向量(本例中取D=32)。 + + ```python + def wordemb(inlayer): + wordemb = table_projection( + input = inlayer, + size = embsize, + param_attr=ParamAttr(name = "_proj", + initial_std=0.001, # 参数初始化标准差 + l2_rate= 0,)) # 词向量不需要稀疏化,因此其l2_rate设为0 + return wordemb + + Efirst = wordemb(firstword) + Esecond = wordemb(secondword) + Ethird = wordemb(thirdword) + Efourth = wordemb(fourthword) + ``` + +3. 接着,将这n-1个词向量经过concat_layer连接成一个大向量作为历史文本特征。 + + ```python + contextemb = concat_layer(input = [Efirst, Esecond, Ethird, Efourth]) + ``` +4. 然后,将历史文本特征经过一个全连接得到文本隐层特征。 + + ```python + hidden1 = fc_layer( + input = contextemb, + size = hiddensize, + act = SigmoidActivation(), + layer_attr = ExtraAttr(drop_rate=0.5), + bias_attr = ParamAttr(learning_rate = 2), + param_attr = ParamAttr( + initial_std = 1./math.sqrt(embsize*8), + learning_rate = 1)) + ``` + +5. 最后,将文本隐层特征,再经过一个全连接,映射成一个$|V|$维向量,同时通过softmax归一化得到这`|V|`个词的生成概率。 + + ```python + # use context embedding to predict nextword + predictword = fc_layer( + input = hidden1, + size = dictsize, + bias_attr = ParamAttr(learning_rate = 2), + act = SoftmaxActivation()) + ``` + +6. 网络的损失函数为多分类交叉熵,可直接调用`classification_cost`函数。 + + ```python + cost = classification_cost( + input = predictword, + label = nextword) + # network input and output + outputs(cost) + ``` + +##训练模型 + +模型训练命令为`./train.sh`。脚本内容如下,其中指定了总共需要执行30个pass。 + +```bash +paddle train \ + --config ngram.py \ + --use_gpu=1 \ + --dot_period=100 \ + --log_period=3000 \ + --test_period=0 \ + --save_dir=model \ + --num_passes=30 +``` + +一个pass的训练日志如下所示: + +```text +............................. +I1222 09:27:16.477841 12590 TrainerInternal.cpp:162] Batch=3000 samples=300000 AvgCost=5.36135 CurrentCost=5.36135 Eval: classification_error_evaluator=0.818653 CurrentEval: class +ification_error_evaluator=0.818653 +............................. +I1222 09:27:22.416700 12590 TrainerInternal.cpp:162] Batch=6000 samples=600000 AvgCost=5.29301 CurrentCost=5.22467 Eval: classification_error_evaluator=0.814542 CurrentEval: class +ification_error_evaluator=0.81043 +............................. +I1222 09:27:28.343756 12590 TrainerInternal.cpp:162] Batch=9000 samples=900000 AvgCost=5.22494 CurrentCost=5.08876 Eval: classification_error_evaluator=0.810088 CurrentEval: class +ification_error_evaluator=0.80118 +..I1222 09:27:29.128582 12590 TrainerInternal.cpp:179] Pass=0 Batch=9296 samples=929600 AvgCost=5.21786 Eval: classification_error_evaluator=0.809647 +I1222 09:27:29.627616 12590 Tester.cpp:111] Test samples=73760 cost=4.9594 Eval: classification_error_evaluator=0.79676 +I1222 09:27:29.627713 12590 GradientMachine.cpp:112] Saving parameters to model/pass-00000 +``` +经过30个pass,我们将得到平均错误率为classification_error_evaluator=0.735611。 + + +## 应用模型 +训练模型后,我们可以加载模型参数,用训练出来的词向量初始化其他模型,也可以将模型参数从二进制格式转换成文本格式进行后续应用。 + +### 初始化其他模型 + +训练好的模型参数可以用来初始化其他模型。具体方法如下: +在PaddlePaddle 训练命令行中,用`--init_model_path` 来定义初始化模型的位置,用`--load_missing_parameter_strategy`指定除了词向量以外的新模型其他参数的初始化策略。注意,新模型需要和原模型共享被初始化参数的参数名。 + +### 查看词向量 +PaddlePaddle训练出来的参数为二进制格式,存储在对应训练pass的文件夹下。这里我们提供了文件`format_convert.py`用来互转PaddlePaddle训练结果的二进制文件和文本格式特征文件。 + +```bash +python format_convert.py --b2t -i INPUT -o OUTPUT -d DIM +``` +其中,INPUT是输入的(二进制)词向量模型名称,OUTPUT是输出的文本模型名称,DIM是词向量参数维度。 + +用法如: + +```bash +python format_convert.py --b2t -i model/pass-00029/_proj -o model/pass-00029/_proj.txt -d 32 +``` +转换后得到的文本文件如下: + +```text +0,4,62496 +-0.7444070,-0.1846171,-1.5771370,0.7070392,2.1963732,-0.0091410, ...... +-0.0721337,-0.2429973,-0.0606297,0.1882059,-0.2072131,-0.7661019, ...... +...... +``` + +其中,第一行是PaddlePaddle 输出文件的格式说明,包含3个属性:
+1) PaddlePaddle的版本号,本例中为0;
+2) 浮点数占用的字节数,本例中为4;
+3) 总计的参数个数, 本例中为62496(即1953*32);
+第二行及之后的每一行都按顺序表示字典里一个词的特征,用逗号分隔。 + +### 修改词向量 + +我们可以对词向量进行修改,并转换成PaddlePaddle参数二进制格式,方法: + +```bash +python format_convert.py --t2b -i INPUT -o OUTPUT +``` + +其中,INPUT是输入的输入的文本词向量模型名称,OUTPUT是输出的二进制词向量模型名称 + +输入的文本格式如下(注意,不包含上面二进制转文本后第一行的格式说明): + +```text +-0.7444070,-0.1846171,-1.5771370,0.7070392,2.1963732,-0.0091410, ...... +-0.0721337,-0.2429973,-0.0606297,0.1882059,-0.2072131,-0.7661019, ...... +...... +``` + + + +### 计算词语之间的余弦距离 + +两个向量之间的距离可以用余弦值来表示,余弦值在$[-1,1]$的区间内,向量间余弦值越大,其距离越近。这里我们在`calculate_dis.py`中实现不同词语的距离度量。 +用法如下: + +```bash +python calculate_dis.py VOCABULARY EMBEDDINGLAYER` +``` + +其中,`VOCABULARY`是字典,`EMBEDDINGLAYER`是词向量模型,示例如下: + +```bash +python calculate_dis.py data/vocabulary.txt model/pass-00029/_proj.txt +``` + + +## 总结 +本章中,我们介绍了词向量、语言模型和词向量的关系、以及如何通过训练神经网络模型获得词向量。在信息检索中,我们可以根据向量间的余弦夹角,来判断query和文档关键词这二者间的相关性。在句法分析和语义分析中,训练好的词向量可以用来初始化模型,以得到更好的效果。在文档分类中,有了词向量之后,可以用聚类的方法将文档中同义词进行分组。希望大家在本章后能够自行运用词向量进行相关领域的研究。 + + +## 参考文献 +1. Bengio Y, Ducharme R, Vincent P, et al. [A neural probabilistic language model](http://www.jmlr.org/papers/volume3/bengio03a/bengio03a.pdf)[J]. journal of machine learning research, 2003, 3(Feb): 1137-1155. +2. Mikolov T, Kombrink S, Deoras A, et al. [Rnnlm-recurrent neural network language modeling toolkit](http://www.fit.vutbr.cz/~imikolov/rnnlm/rnnlm-demo.pdf)[C]//Proc. of the 2011 ASRU Workshop. 2011: 196-201. +3. Mikolov T, Chen K, Corrado G, et al. [Efficient estimation of word representations in vector space](https://arxiv.org/pdf/1301.3781.pdf)[J]. arXiv preprint arXiv:1301.3781, 2013. +4. Maaten L, Hinton G. [Visualizing data using t-SNE](https://lvdmaaten.github.io/publications/papers/JMLR_2008.pdf)[J]. Journal of Machine Learning Research, 2008, 9(Nov): 2579-2605. +5. https://en.wikipedia.org/wiki/Singular_value_decomposition diff --git a/word2vec/calculate_dis.py b/word2vec/calculate_dis.py new file mode 100755 index 0000000000000000000000000000000000000000..a18e5ffee11a3178526255bc27ab4479583d408e --- /dev/null +++ b/word2vec/calculate_dis.py @@ -0,0 +1,77 @@ +# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +""" +Example: + python calculate_dis.py DICTIONARYTXT FEATURETXT + +Required arguments: + DICTIONARYTXT the dictionary generated in dataprovider + FEATURETXT the text format word feature, one line for one word +""" + +import numpy as np +from argparse import ArgumentParser + + +def load_dict(fdict): + words = [line.strip() for line in fdict.readlines()] + dictionary = dict(zip(words, xrange(len(words)))) + return dictionary + + +def load_emb(femb): + feaBank = [] + flag_firstline = True + for line in femb: + if flag_firstline: + flag_firstline = False + continue + fea = np.array([float(x) for x in line.strip().split(',')]) + normfea = fea * 1.0 / np.linalg.norm(fea) + feaBank.append(normfea) + return feaBank + + +def calcos(id1, id2, Fea): + f1 = Fea[id1] + f2 = Fea[id2] + return np.dot(f1.transpose(), f2) + + +def get_wordidx(w, Dict): + if w not in Dict: + print 'ERROR: %s not in the dictionary' % w + return -1 + return Dict[w] + + +if __name__ == '__main__': + parser = ArgumentParser() + parser.add_argument('dict', help='dictionary file') + parser.add_argument('fea', help='feature file') + args = parser.parse_args() + + with open(args.dict) as fdict: + word_dict = load_dict(fdict) + + with open(args.fea) as ffea: + word_fea = load_emb(ffea) + + while True: + w1, w2 = raw_input("please input two words: ").split() + w1_id = get_wordidx(w1, word_dict) + w2_id = get_wordidx(w2, word_dict) + if w1_id == -1 or w2_id == -1: + continue + print 'similarity: %s' % (calcos(w1_id, w2_id, word_fea)) diff --git a/word2vec/data/getdata.sh b/word2vec/data/getdata.sh new file mode 100755 index 0000000000000000000000000000000000000000..7b9e938640add251df4b8f1c61277b1c1eed61c6 --- /dev/null +++ b/word2vec/data/getdata.sh @@ -0,0 +1,7 @@ +#!/bin/bash +set -e + +wget http://www.fit.vutbr.cz/~imikolov/rnnlm/simple-examples.tgz +tar -zxf simple-examples.tgz +echo `pwd`/simple-examples/data/ptb.train.txt > train.list +echo `pwd`/simple-examples/data/ptb.valid.txt > test.list diff --git a/word2vec/dataprovider.py b/word2vec/dataprovider.py new file mode 100644 index 0000000000000000000000000000000000000000..2f48d4f0fb17b84696f85f1df4cc558082ea9eed --- /dev/null +++ b/word2vec/dataprovider.py @@ -0,0 +1,63 @@ +# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from paddle.trainer.PyDataProvider2 import * +import collections +import logging +import pdb + +logging.basicConfig( + format='[%(levelname)s %(asctime)s %(filename)s:%(lineno)s] %(message)s', ) +logger = logging.getLogger('paddle') +logger.setLevel(logging.INFO) + +N = 5 # Ngram +cutoff = 50 # select words with frequency > cutoff to dictionary + + +def build_dict(ftrain, fdict): + sentences = [] + with open(ftrain) as fin: + for line in fin: + line = [''] + line.strip().split() + [''] + sentences += line + wordfreq = collections.Counter(sentences) + wordfreq = filter(lambda x: x[1] > cutoff, wordfreq.items()) + dictionary = sorted(wordfreq, key=lambda x: (-x[1], x[0])) + words, _ = list(zip(*dictionary)) + for word in words: + print >> fdict, word + word_idx = dict(zip(words, xrange(len(words)))) + logger.info("Dictionary size=%s" % len(words)) + return word_idx + + +def initializer(settings, srcText, dictfile, **xargs): + with open(dictfile, 'w') as fdict: + settings.dicts = build_dict(srcText, fdict) + input_types = [] + for i in xrange(N): + input_types.append(integer_value(len(settings.dicts))) + settings.input_types = input_types + + +@provider(init_hook=initializer) +def process(settings, filename): + UNKID = settings.dicts[''] + with open(filename) as fin: + for line in fin: + line = [''] * (N - 1) + line.strip().split() + [''] + line = [settings.dicts.get(w, UNKID) for w in line] + for i in range(N, len(line) + 1): + yield line[i - N:i] diff --git a/word2vec/format_convert.py b/word2vec/format_convert.py new file mode 100755 index 0000000000000000000000000000000000000000..f12ad81c0aa0d532d6f337d41479228f5b04ebc9 --- /dev/null +++ b/word2vec/format_convert.py @@ -0,0 +1,158 @@ +# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +""" +Example: + python format_convert.py --b2t -i INPUT -o OUTPUT -d DIM + python format_convert.py --t2b -i INPUT -o OUTPUT + +Options: + -h, --help show this help message and exit + --b2t convert parameter file of embedding model from binary to text + --t2b convert parameter file of embedding model from text to binary + -i INPUT input parameter file name + -o OUTPUT output parameter file name + -d DIM dimension of parameter +""" +from optparse import OptionParser +import struct + + +def binary2text(input, output, paraDim): + """ + Convert a binary parameter file of embedding model to be a text file. + input: the name of input binary parameter file, the format is: + 1) the first 16 bytes is filehead: + version(4 bytes): version of paddle, default = 0 + floatSize(4 bytes): sizeof(float) = 4 + paraCount(8 bytes): total number of parameter + 2) the next (paraCount * 4) bytes is parameters, each has 4 bytes + output: the name of output text parameter file, for example: + 0,4,32156096 + -0.7845433,1.1937413,-0.1704215,... + 0.0000909,0.0009465,-0.0008813,... + ... + the format is: + 1) the first line is filehead: + version=0, floatSize=4, paraCount=32156096 + 2) other lines print the paramters + a) each line prints paraDim paramters splitted by ',' + b) there is paraCount/paraDim lines (embedding words) + paraDim: dimension of parameters + """ + fi = open(input, "rb") + fo = open(output, "w") + """ + """ + version, floatSize, paraCount = struct.unpack("iil", fi.read(16)) + newHead = ','.join([str(version), str(floatSize), str(paraCount)]) + print >> fo, newHead + + bytes = 4 * int(paraDim) + format = "%df" % int(paraDim) + context = fi.read(bytes) + line = 0 + + while context: + numbers = struct.unpack(format, context) + lst = [] + for i in numbers: + lst.append('%8.7f' % i) + print >> fo, ','.join(lst) + context = fi.read(bytes) + line += 1 + fi.close() + fo.close() + print "binary2text finish, total", line, "lines" + + +def get_para_count(input): + """ + Compute the total number of embedding parameters in input text file. + input: the name of input text file + """ + numRows = 1 + paraDim = 0 + with open(input) as f: + line = f.readline() + paraDim = len(line.split(",")) + for line in f: + numRows += 1 + return numRows * paraDim + + +def text2binary(input, output, paddle_head=True): + """ + Convert a text parameter file of embedding model to be a binary file. + input: the name of input text parameter file, for example: + -0.7845433,1.1937413,-0.1704215,... + 0.0000909,0.0009465,-0.0008813,... + ... + the format is: + 1) it doesn't have filehead + 2) each line stores the same dimension of parameters, + the separator is commas ',' + output: the name of output binary parameter file, the format is: + 1) the first 16 bytes is filehead: + version(4 bytes), floatSize(4 bytes), paraCount(8 bytes) + 2) the next (paraCount * 4) bytes is parameters, each has 4 bytes + """ + fi = open(input, "r") + fo = open(output, "wb") + + newHead = struct.pack("iil", 0, 4, get_para_count(input)) + fo.write(newHead) + + count = 0 + for line in fi: + line = line.strip().split(",") + for i in range(0, len(line)): + binary_data = struct.pack("f", float(line[i])) + fo.write(binary_data) + count += 1 + fi.close() + fo.close() + print "text2binary finish, total", count, "lines" + + +def main(): + """ + Main entry for running format_convert.py + """ + usage = "usage: \n" \ + "python %prog --b2t -i INPUT -o OUTPUT -d DIM \n" \ + "python %prog --t2b -i INPUT -o OUTPUT" + parser = OptionParser(usage) + parser.add_option( + "--b2t", + action="store_true", + help="convert parameter file of embedding model from binary to text") + parser.add_option( + "--t2b", + action="store_true", + help="convert parameter file of embedding model from text to binary") + parser.add_option( + "-i", action="store", dest="input", help="input parameter file name") + parser.add_option( + "-o", action="store", dest="output", help="output parameter file name") + parser.add_option( + "-d", action="store", dest="dim", help="dimension of parameter") + (options, args) = parser.parse_args() + if options.b2t: + binary2text(options.input, options.output, options.dim) + if options.t2b: + text2binary(options.input, options.output) + + +if __name__ == '__main__': + main() diff --git a/word2vec/image/2d_similarity.png b/word2vec/image/2d_similarity.png new file mode 100644 index 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0000000000000000000000000000000000000000..b6f08fa8a3ca4c891a8c55532d9324c2d238c780 Binary files /dev/null and b/word2vec/image/sentence_emb.png differ diff --git a/word2vec/image/skipgram.png b/word2vec/image/skipgram.png new file mode 100644 index 0000000000000000000000000000000000000000..92f7c370383175538b62c28618c723c8916074bb Binary files /dev/null and b/word2vec/image/skipgram.png differ diff --git a/word2vec/ngram.py b/word2vec/ngram.py new file mode 100644 index 0000000000000000000000000000000000000000..13d6291dc5b3886c42c18e80af413b36bdb724e1 --- /dev/null +++ b/word2vec/ngram.py @@ -0,0 +1,84 @@ +# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from paddle.trainer_config_helpers import * + +import math + +#################### Data Configure #################### +args = { + 'srcText': 'data/simple-examples/data/ptb.train.txt', + 'dictfile': 'data/vocabulary.txt' +} +define_py_data_sources2( + train_list="data/train.list", + test_list="data/test.list", + module="dataprovider", + obj="process", + args=args) + +settings( + batch_size=100, regularization=L2Regularization(8e-4), learning_rate=3e-3) + +dictsize = 1953 +embsize = 32 +hiddensize = 256 + +firstword = data_layer(name="firstw", size=dictsize) +secondword = data_layer(name="secondw", size=dictsize) +thirdword = data_layer(name="thirdw", size=dictsize) +fourthword = data_layer(name="fourthw", size=dictsize) +nextword = data_layer(name="fifthw", size=dictsize) + + +# construct word embedding for each datalayer +def wordemb(inlayer): + wordemb = table_projection( + input=inlayer, + size=embsize, + param_attr=ParamAttr( + name="_proj", + initial_std=0.001, + learning_rate=1, + l2_rate=0, )) + return wordemb + + +Efirst = wordemb(firstword) +Esecond = wordemb(secondword) +Ethird = wordemb(thirdword) +Efourth = wordemb(fourthword) + +# concatentate Ngram embeddings into context embedding +contextemb = concat_layer(input=[Efirst, Esecond, Ethird, Efourth]) +hidden1 = fc_layer( + input=contextemb, + size=hiddensize, + act=SigmoidActivation(), + layer_attr=ExtraAttr(drop_rate=0.5), + bias_attr=ParamAttr(learning_rate=2), + param_attr=ParamAttr( + initial_std=1. / math.sqrt(embsize * 8), learning_rate=1)) + +# use context embedding to predict nextword +predictword = fc_layer( + input=hidden1, + size=dictsize, + bias_attr=ParamAttr(learning_rate=2), + act=SoftmaxActivation()) + +cost = classification_cost(input=predictword, label=nextword) + +# network input and output +outputs(cost) diff --git a/word2vec/train.sh b/word2vec/train.sh new file mode 100755 index 0000000000000000000000000000000000000000..1e7a7753aeed45e34165539ab34c2792ec8e8196 --- /dev/null +++ b/word2vec/train.sh @@ -0,0 +1,11 @@ +#!/bin/bash +set -e + +paddle train \ + --config ngram.py \ + --use_gpu=1 \ + --dot_period=100 \ + --log_period=3000 \ + --test_period=0 \ + --save_dir=model \ + --num_passes=30