在R中使用tm包进行预处理时出错

Question

I am trying to do some preprocessing with tm package in R. I wrote the lines below:

corpus <- Corpus(VectorSource(Data))
corpus <- tm_map(corpus , asPlain)
corpus <- tmMap(corpus , removeSignature)

As you can see, I tried both 'tm_map' and 'tmMap'. But I faced these errors each time:

Error in match.fun(FUN) : object 'asPlain' not found
Error: could not find function "tmMap"

Could you please help me to solve this error?

Answer 1

The tm package changed the function calls and some of those methods are no longer available.

Here is some sample code with the new functions.

require(tm)
text_corpus <- VCorpus( DirSource("20ng_train/sci.electronics"))
corpus_clean <- tm_map(text_corpus, content_transformer(tolower))
corpus_clean <- tm_map(corpus_clean, removeNumbers) 
corpus_clean <- tm_map(corpus_clean, removeWords, stopwords()) 
corpus_clean <- tm_map(corpus_clean, removePunctuation)
corpus_clean <- tm_map(corpus_clean, stemDocument)
corpus_clean <- tm_map(corpus_clean, stripWhitespace)