将语料库转换为数据帧将返回NA's

Question

我正在尝试将我的语料库转换回一个数据框，但它仅返回NA。请帮助

代码：

library(wordcloud)
df <- data.frame(Description = c("I like this service very much"," this is worth it so much"))

corpus <- Corpus(VectorSource(df$Description))

corpus <- tm_map(corpus, tolower)

corpus <- tm_map(corpus, removePunctuation)
corpus <- tm_map(corpus, removeWords, c(stopwords('english')))
corpus <- tm_map(corpus, stripWhitespace)
corpus <- tm_map(corpus, stemDocument)

#a <- as.data.frame(corpus)

dataframe<-data.frame(text=unlist(sapply(corpus, `[`, "content")), 
                      stringsAsFactors=F)

预期输出：

数据框

'like servic much'
'worth much'

Answer 1

以下代码对我有用：

dataframe <- data.frame(text = sapply(corpus, as.character), stringsAsFactors = FALSE)

输出：

              text
1 like servic much
2       worth much