我希望您能够协助进行文本挖掘练习。我对“AAPL”推文很感兴趣,并且能够从 API 中提取 500 条推文。我能够自己清除几个障碍,但最后一部分需要帮助。出于某种原因, tm 包没有删除停用词。你能看看,看看可能是什么问题?表情符号会导致问题吗?
绘制 Term_Frequency 后,最常见的术语是“AAPL”、“Apple”、“iPhone”、“Price”、“Stock”
提前致谢!
芒金
transform into dataframe
tweets.df <- twListToDF(tweets)
#Isolate text from tweets
aapl_tweets <- tweets.df$text
#Deal with emoticons
tweets2 <- data.frame(text = iconv(aapl_tweets, "latin1", "ASCII", "bye"), stringsAsFactors = FALSE)
#Make a vector source:
aapl_source <- VectorSource(tweets2)
#make a volatile corpus
aapl_corpus <- VCorpus(aapl_source)
aapl_cleaned <- clean_corpus(aapl_source)
#create my list to remove words
myList <- c("aapl", "apple", "stock", "stocks", stopwords("en"))
#clean corpus function
clean_corpus <- function(corpus){
corpus <- tm_map(corpus, stripWhitespace, mc.cores = 1)
corpus <- tm_map(corpus, removePunctuation, mc.cores = 1)
corpus <- tm_map(corpus, removeWords, myList, mc.cores = 1)
return(corpus)
}
#clean aapl corpus
aapl_cleaned <- clean_corpus(aapl_corpus)
#convert to TDM
aapl.tdm <- TermDocumentMatrix(aapl_cleaned)
aapl.tdm
#Convert as Matrix
aapl_m <- as.matrix(aapl.tdm)
#Create Frequency tables
term_frequency <- rowSums(aapl_m)
term_frequency <- sort(term_frequency, decreasing = TRUE)
term_frequency[1:10]
barplot(term_frequency[1:10])