我正在尝试对已经获取并存储在 MongoDb 中的推文进行情感分析。获取数据框格式的推文后,我收到以下错误:
ip.txt=laply(ip.lst,function(t) t$getText())
Error in t$getText : $ operator is invalid for atomic vectors
整个代码如下:
iphone.tweets <- searchTwitter('#iphone', n=15, lang="en")
iphone.text=laply(iphone.tweets,function(t) t$getText())
df_ip <- as.data.frame(iphone.text)
m <- mongo("iphonecollection",db="project")
m$insert(df_ip)
df_ip<-m$find()
ip.lst<-as.list(t(df_ip))
ip.txt=laply(ip.lst,function(t) t$getText())
我想要做的是计算情绪分数如下:
iphone.scores <- score.sentiment(ip.txt, pos.words,neg.words, .progress='text')
score.sentiment 例程如下:
score.sentiment = function(sentences, pos.words, neg.words, .progress='none')
{
require(plyr)
require(stringr)
# we got a vector of sentences. plyr will handle a list or a vector as an "l" for us
# we want a simple array of scores back, so we use "l" + "a" + "ply" = laply:
scores = laply(sentences, function(sentence, pos.words, neg.words) {
# clean up sentences with R's regex-driven global substitute, gsub():
sentence = gsub('[[:punct:]]', '', sentence)
sentence = gsub('[[:cntrl:]]', '', sentence)
sentence = gsub('\\d+', '', sentence)
# and convert to lower case:
sentence = tolower(sentence)
# split into words. str_split is in the stringr package
word.list = str_split(sentence, '\\s+')
# sometimes a list() is one level of hierarchy too much
words = unlist(word.list)
# compare our words to the dictionaries of positive & negative terms
pos.matches = match(words, pos.words)
neg.matches = match(words, neg.words)
# match() returns the position of the matched term or NA
# we just want a TRUE/FALSE:
pos.matches = !is.na(pos.matches)
neg.matches = !is.na(neg.matches)
# and conveniently enough, TRUE/FALSE will be treated as 1/0 by sum():
score = sum(pos.matches) - sum(neg.matches)
return(score)
}, pos.words, neg.words, .progress=.progress )
scores.df = data.frame(score=scores, text=sentences)
return(scores.df)
}