小编mom*_*obo的帖子

我对tm r库有一个(小)问题.说我有一个语料库:

# boilerplate
bcorp <- c("one","two","three","four","five")
myCorpus <- Corpus(VectorSource(bcorp), list(lanuage = "en_US"))
tdm <- TermDocumentMatrix(myCorpus)
Docs(tdm)

结果:

[1] "1" "2" "3" "4" "5"

这有效.但是当我尝试使用转换tm_map()时:

# this does not work
myCorpus <- Corpus(VectorSource(bcorp), list(lanuage = "en_US"))
myCorpus <- tm_map(myCorpus, tolower)
tdm <- TermDocumentMatrix(myCorpus)

给

Error: inherits(doc, "TextDocument") is not TRUE

在这种情况下提出的解决方案是转换为PlainTextDocument.

# this works but erase the metadata
myCorpus <- Corpus(VectorSource(bcorp), list(lanuage = "en_US"))
myCorpus <- tm_map(myCorpus, tolower)
myCorpus <- tm_map(myCorpus, PlainTextDocument)
tdm <- TermDocumentMatrix(myCorpus)
Docs(tdm)

结果:

[1] "character(0)" "character(0)" …