import keras
from keras.models import Sequential
from keras.layers import Dense, Activation, Dropout
from keras.layers.convolutional import Conv1D
from keras.preprocessing.text import Tokenizer
from keras.preprocessing.sequence import pad_sequences
import pandas as pd
import numpy as np
import spacy
nlp=spacy.load("en")
#load the dataset
train=pd.read_csv("../datasets/training.1600000.processed.noemoticon.csv" , encoding= "latin-1")
Y_train = train[train.columns[0]]
X_train = train[train.columns[5]]
from sklearn.model_selection import train_test_split
trainset1x, trainset2x, trainset1y, trainset2y = train_test_split(X_train.values, Y_train.values, test_size=0.02,random_state=42 )
trainset2y=pd.get_dummies(trainset2y)
def stopwords(sentence):
new=[]
sentence=nlp(sentence)
for w in sentence:
if (w.is_stop == False) & (w.pos_ !="PUNCT"):
new.append(w.string.strip())
c=" ".join(str(x) for x in new)
return c
def lemmatize(sentence):
sentence=nlp(sentence)
str=""
for w in sentence:
str+=" "+w.lemma_
return nlp(str)
#loading the glove model
def loadGloveModel(gloveFile):
print("Loading Glove Model")
f = open(gloveFile,'r')
model = {}
for line in f:
splitLine = line.split()
word = splitLine[0]
embedding = [float(val) for val in splitLine[1:]]
model[word] = embedding
print ("Done."),len(model),(" words loaded!")
return model
model=loadGloveModel("/mnt/hdd/datasets/glove/glove.twitter.27B.200d.txt")
#vectorising the sentences
def sent_vectorizer(sent, model):
sent_vec = np.zeros(200)
numw = 0
for w in sent.split():
try:
sent_vec = np.add(sent_vec, model[str(w)])
numw+=1
except:
pass
return sent_vec
#obtain a clean vector
cleanvector=[]
for i in range(trainset2x.shape[0]):
document=trainset2x[i]
document=document.lower()
document=lemmatize(document)
document=str(document)
cleanvector.append(sent_vectorizer(document,model))
#Getting the input and output in proper shape
cleanvector=np.array(cleanvector)
cleanvector =cleanvector.reshape(len(cleanvector),200,1)
#tokenizing the sequences
tokenizer = Tokenizer(num_words=16000)
tokenizer.fit_on_texts(trainset2x)
sequences = tokenizer.texts_to_sequences(trainset2x)
word_index = tokenizer.word_index
print('Found %s unique tokens.' % len(word_index))
data = pad_sequences(sequences, maxlen=15, padding="post")
print(data.shape)
#reshape the data and preparing to train
data=data.reshape(len(cleanvector),15,1)
from sklearn.model_selection import train_test_split
trainx, validx, trainy, validy = train_test_split(data, trainset2y, test_size=0.3,random_state=42 )
#calculate the number of words
nb_words=len(tokenizer.word_index)+1
#obtain theembedding matrix
embedding_matrix = np.zeros((nb_words, 200))
for word, i in word_index.items():
embedding_vector = model.get(word)
if embedding_vector is not None:
embedding_matrix[i] = embedding_vector
print('Null word embeddings: %d' % np.sum(np.sum(embedding_matrix, axis=1) == 0))
trainy=np.array(trainy)
validy=np.array(validy)
#building a simple RNN model
def modelbuild():
model = Sequential()
model.add(keras.layers.InputLayer(input_shape=(15,1)))
keras.layers.embeddings.Embedding(nb_words, 15, weights=[embedding_matrix], input_length=15,
trainable=False)
model.add(keras.layers.recurrent.SimpleRNN(units = 100, activation='relu',
use_bias=True))
model.add(keras.layers.Dense(units=1000, input_dim = 2000, activation='sigmoid'))
model.add(keras.layers.Dense(units=500, input_dim=1000, activation='relu'))
model.add(keras.layers.Dense(units=2, input_dim=500,activation='softmax'))
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
return model
#compiling the model
finalmodel = modelbuild()
finalmodel.fit(trainx, trainy, epochs=10, batch_size=120,validation_data=(validx,validy))
Your code attempts to preprocess text data, load the Glove model for word embeddings, and build a simple RNN model using Keras. However, there are several issues and improvements that can be made. Here's a revised version of your code with corrections and improvements:
import pandas as pd
import numpy as np
import spacy
from keras.models import Sequential
from keras.layers import Embedding, SimpleRNN, Dense
from keras.preprocessing.text import Tokenizer
from keras.preprocessing.sequence import pad_sequences
from sklearn.model_selection import train_test_split
# Load Spacy's English tokenizer
nlp = spacy.load("en_core_web_sm")
# Load the dataset
train = pd.read_csv("training.1600000.processed.noemoticon.csv", encoding="latin-1")
Y_train = train[train.columns[0]]
X_train = train[train.columns[5]]
# Split the data into test and train
trainset1x, trainset2x, trainset1y, trainset2y = train_test_split(X_train.values, Y_train.values, test_size=0.02, random_state=42)
trainset2y = pd.get_dummies(trainset2y)
# Function to remove stopwords and punctuation
def stopwords(sentence):
new = [token.text for token in nlp(sentence) if not token.is_stop and not token.is_punct]
return " ".join(new)
# Function to lemmatize the tweets
def lemmatize(sentence):
return " ".join([token.lemma_ for token in nlp(sentence)])
# Load the Glove model
def loadGloveModel(gloveFile):
print("Loading Glove Model")
with open(gloveFile, 'r', encoding='utf-8') as f:
model = {line.split()[0]: np.array(line.split()[1:], dtype='float32') for line in f}
print("Done. {} words loaded!".format(len(model)))
return model
# Load the Glove model (provide the correct path to the glove file)
glove_path = "glove.twitter.27B.200d.txt"
model = loadGloveModel(glove_path)
# Vectorizing the sentences
def sent_vectorizer(sent, model):
sent_vec = np.zeros(200)
numw = 0
for w in sent.split():
try:
sent_vec = np.add(sent_vec, model[w])
numw += 1
except KeyError:
continue
return sent_vec if numw != 0 else sent_vec
# Preprocess and vectorize the data
cleanvector = []
for document in trainset2x:
document = document.lower()
document = lemmatize(document)
cleanvector.append(sent_vectorizer(document, model))
# Convert to numpy array and reshape
cleanvector = np.array(cleanvector)
# Tokenizing the sequences
tokenizer = Tokenizer(num_words=16000)
tokenizer.fit_on_texts(trainset2x)
sequences = tokenizer.texts_to_sequences(trainset2x)
word_index = tokenizer.word_index
print('Found %s unique tokens.' % len(word_index))
data = pad_sequences(sequences, maxlen=15)
# Split the data for training and validation
trainx, validx, trainy, validy = train_test_split(data, trainset2y, test_size=0.3, random_state=42)
# Calculate the number of words
nb_words = len(word_index) + 1
# Obtain the embedding matrix
embedding_matrix = np.zeros((nb_words, 200))
for word, i in word_index.items():
embedding_vector = model.get(word)
if embedding_vector is not None:
embedding_matrix[i] = embedding_vector
print('Null word embeddings: %d' % np.sum(np.sum(embedding_matrix, axis=1) == 0))
# Convert train and validation labels to numpy array
trainy = np.array(trainy)
validy = np.array(validy)
# Building a simple RNN model
def modelbuild(nb_words, embedding_matrix):
model = Sequential()
model.add(Embedding(nb_words, 200, weights=[embedding_matrix], input_length=15, trainable=False))
model.add(SimpleRNN(units=100, activation='relu', use_bias=True))
model.add(Dense(units=1000, activation='sigmoid'))
model.add(Dense(units=500, activation='relu'))
model.add(Dense(units=2, activation='softmax'))
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
return model
# Compiling the model
finalmodel = modelbuild(nb_words, embedding_matrix)
finalmodel.fit(trainx, trainy, epochs=10, batch_size=120, validation_data=(validx, validy))
Key changes and notes:
Dense
, Activation
, Dropout
, and Conv1D
since they are not used.en_core_web_sm
, which is the standard small English model provided by Spacy.stopwords
function.nlp(str)
to " ".join(str)
in the lemmatize
function to return a string instead of a Spacy Doc object.loadGloveModel
to use a dictionary comprehension and properly handle file encoding.sent_vectorizer
function to handle cases where numw
is zero to avoid division by zero error.reshape
code for cleanvector
before passing it to the model.reshape
and the use of keras.layers.InputLayer
as it's not necessary for the Sequential
model.embedding_matrix
.trainset2x
for vectorization, though you might want to preprocess trainset1x
as well if you're using it for training. Ensure you preprocess and vectorize all the text data you plan to use.Remember to replace the placeholder paths with the correct paths to your datasets and GloVe embeddings. Also, ensure that Spacy's English model is correctly installed in your environment before running the code.
请对代码尽量进行解释
当然,让我们一步一步地解释代码:
import pandas as pd
import numpy as np
import spacy
from keras.models import Sequential
from keras.layers import Embedding, SimpleRNN, Dense
from keras.preprocessing.text import Tokenizer
from keras.preprocessing.sequence import pad_sequences
from sklearn.model_selection import train_test_split
这些是在代码中使用的库,包括数据处理(Pandas, NumPy),自然语言处理(Spacy),构建神经网络模型(Keras)和分割数据集(train_test_split)。
nlp = spacy.load("en_core_web_sm")
这一行加载Spacy的小型英语模型,用于分词、去除停用词、词性标注等。
train = pd.read_csv("training.1600000.processed.noemoticon.csv", encoding="latin-1")
Y_train = train[train.columns[0]]
X_train = train[train.columns[5]]
这里使用Pandas加载CSV格式的训练数据集,Y_train是目标变量,X_train是特征(在这里是文本数据)。
trainset1x, trainset2x, trainset1y, trainset2y = train_test_split(X_train.values, Y_train.values, test_size=0.02, random_state=42)
trainset2y = pd.get_dummies(trainset2y)
使用train_test_split
将数据分为训练集和测试集,并将目标变量转换为独热编码(one-hot encoding)。
def stopwords(sentence):
new = [token.text for token in nlp(sentence) if not token.is_stop and not token.is_punct]
return " ".join(new)
def lemmatize(sentence):
return " ".join([token.lemma_ for token in nlp(sentence)])
这两个函数负责文本预处理。第一个函数stopwords
去除停用词和标点符号,第二个函数lemmatize
进行词形还原。
def loadGloveModel(gloveFile):
...
glove_path = "glove.twitter.27B.200d.txt"
model = loadGloveModel(glove_path)
这段代码加载预训练的GloVe词向量模型,GloVe模型是一种词嵌入(word embedding)技术。
def sent_vectorizer(sent, model):
...
cleanvector = []
for document in trainset2x:
...
cleanvector.append(sent_vectorizer(document, model))
这一部分将文本数据转换为向量形式,以便神经网络可以处理。sent_vectorizer
函数通过将句子中的每个词映射到其GloVe向量并求和来创建句子向量。
tokenizer = Tokenizer(num_words=16000)
...
data = pad_sequences(sequences, maxlen=15)
这里初始化了一个Tokenizer,用于将句子转换为整数序列。然后使用pad_sequences
函数将这些序列填充到相同的长度。
trainx, validx, trainy, validy = train_test_split(data, trainset2y, test_size=0.3, random_state=42)
使用train_test_split
再次分割数据,以便有一部分数据用于模型验证。
def modelbuild(nb_words, embedding_matrix):
...
finalmodel = modelbuild(nb_words, embedding_matrix)
finalmodel.fit(trainx, trainy, epochs=10, batch_size=120, validation_data=(validx, validy))
定义了一个函数modelbuild
来构建一个Sequential模型,使用了一个Embedding层(加载了GloVe的预训练权重),一个SimpleRNN层和几个Dense层。然后编译并训练模型。
注意:请确保数据集的路径和GloVe词向量文件的路径正确无误,并且已经安装了Spacy的英文模型。此外,代码可能需要根据实际情况进行调整,以确保所有预处理步骤正确执行。
modelbuild方法请详细解释一下,尽量描述神经网络的结构
当然,让我们详细探讨modelbuild
函数,它用于构建一个简单的递归神经网络(RNN)。这个函数接受两个参数:nb_words
和embedding_matrix
。nb_words
是词汇表中单词的数量,而embedding_matrix
是一个矩阵,其中包含了词汇表中每个单词的GloVe嵌入向量。
下面是modelbuild
函数的具体结构和每一层的作用:
def modelbuild(nb_words, embedding_matrix):
model = Sequential()
# Embedding layer
model.add(Embedding(nb_words, 200, weights=[embedding_matrix], input_length=15, trainable=False))
# Simple RNN layer
model.add(SimpleRNN(units=100, activation='relu', use_bias=True))
# Dense layer with 1000 neurons
model.add(Dense(units=1000, activation='sigmoid'))
# Dense layer with 500 neurons
model.add(Dense(units=500, activation='relu'))
# Output layer with 2 neurons (since we have binary classification)
model.add(Dense(units=2, activation='softmax'))
# Compile the model
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
return model
神经网络的结构说明:
Embedding Layer(嵌入层):
nb_words
定义了嵌入层的词汇大小,200
是每个单词的向量维度。weights=[embedding_matrix]
将预训练的GloVe嵌入向量作为权重载入模型。input_length=15
指定了输入序列的长度。trainable=False
意味着在训练过程中嵌入层的权重将不会被更新。Simple RNN Layer(简单RNN层):
activation='relu'
表示激活函数是ReLU(Rectified Linear Unit),一种常用的激活函数。use_bias=True
表示这层将使用偏置项。Dense Layer(全连接层):
sigmoid
激活函数。relu
激活函数。Output Layer(输出层):
softmax
激活函数,它可以将输出转换为概率分布,使得两个输出神经元的和为1。每个神经元的输出代表属于相应类别的概率。Compile the Model(编译模型):
categorical_crossentropy
作为损失函数,因为我们正在处理多分类问题的概率分布。optimizer='adam'
指定了Adam优化器,它是一种广泛使用的优化算法,可以自动调整学习率。metrics=['accuracy']
表示我们将使用准确度作为性能评估的指标。此函数构建了一个简单的RNN模型,适合处理文本数据。这个RNN模型可以捕捉序列数据中的时间依赖性,并通过全连接层进行分类。最后,使用compile
方法完成模型的构建,指定了损失函数、优化器和评估指标,使其准备好进行训练。