首页 > IT职业 > IT生活 > LDA主题模型简介及Python实现
import gensim
from gensim import corpora
import matplotlib.pyplot as plt
import matplotlib
import numpy as np
import warnings
warnings.filterwarnings('ignore') # To ignore all warnings that arise here to enhance clarity
from gensim.models.coherencemodel import CoherenceModel
from gensim.models.ldamodel import LdaModel
# 准备数据
PATH = "E:/data/output.csv"
file_object2=open(PATH,encoding = 'utf-8',errors = 'ignore').read().split('\n') # 一行行的读取内容
data_set=[] # 建立存储分词的列表
for i in range(len(file_object2)):
result=[]
seg_list = file_object2[i].split()
for w in seg_list :# 读取每一行分词
result.append(w)
data_set.append(result)
print(data_set)
dictionary = corpora.Dictionary(data_set) # 构建 document-term matrix
corpus = [dictionary.doc2bow(text) for text in data_set]
#Lda = gensim.models.ldamodel.LdaModel # 创建 LDA 对象
# 计算困惑度
def perplexity(num_topics):
ldamodel = LdaModel(corpus, num_topics=num_topics, id2word = dictionary, passes=30)
print(ldamodel.print_topics(num_topics=num_topics, num_words=15))
print(ldamodel.log_perplexity(corpus))
return ldamodel.log_perplexity(corpus)
# 计算 coherence
def coherence(num_topics):
ldamodel = LdaModel(corpus, num_topics=num_topics, id2word = dictionary, passes=30,random_state = 1)
print(ldamodel.print_topics(num_topics=num_topics, num_words=10))
ldacm = CoherenceModel(model=ldamodel, texts=data_set, dictionary=dictionary, coherence='c_v')
print(ldacm.get_coherence())
return ldacm.get_coherence()
# 绘制困惑度折线图
x = range(1,15)
# z = [perplexity(i) for i in x]
y = [coherence(i) for i in x]
plt.plot(x, y)
plt.xlabel(' 主题数目 ')
plt.ylabel('coherence 大小 ')
plt.rcParams['font.sans-serif']=['SimHei']
matplotlib.rcParams['axes.unicode_minus']=False
plt.title(' 主题 -coherence 变化情况 ')
plt.show()
from gensim.models import LdaModel
import pandas as pd
from gensim.corpora import Dictionary
from gensim import corpora, models
import csv
# 准备数据
PATH = "E:/data/output1.csv"
file_object2=外汇跟单gendan5.comopen(PATH,encoding = 'utf-8',errors = 'ignore').read().split('\n') # 一行行的读取内容
data_set=[] # 建立存储分词的列表
for i in range(len(file_object2)):
result=[]
seg_list = file_object2[i].split()
for w in seg_list :# 读取每一行分词
result.append(w)
data_set.append(result)
dictionary = corpora.Dictionary(data_set) # 构建 document-term matrix
corpus = [dictionary.doc2bow(text) for text in data_set]
lda = LdaModel(corpus=corpus, id2word=dictionary, num_topics=5, passes = 30,random_state=1)
topic_list=lda.print_topics()
print(topic_list)
result_list =[]
for i in lda.get_document_topics(corpus)[:]:
listj=[]
for j in i:
listj.append(j[1])
bz=listj.index(max(listj))
result_list.append(i[bz][0])
print(result_list)
import pyLDAvis.gensim
pyLDAvis.enable_notebook()
data = pyLDAvis.gensim.prepare(lda, corpus, dictionary)
pyLDAvis.save_html(data, 'E:/data/topic.html')
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