How to convert Data Frame to Term Document Matrix in R?

Question

I have a table (Data frame) myTable with a single column as follows:

         sentence
1      it is a window
2      My name is john doe
3      Thank you
4      Good luck
.
.
.

I want to convert it to a Term Document Matrix in R. I did this:

tdm_s <- TermDocumentMatrix(Corpus(DataframeSource(myTable)))

but I got this error:

Error: all(!is.na(match(c("doc_id", "text"), names(x)))) is not TRUE

I googled and couldn't find anything. How can I do this conversion?

Answer 1

You would need to do as below to convert into Term Document Matrix:

## Your sample data
myTable <- data.frame(sentence = c("it is a window", "My name is john doe", "Thank you", "Good luck"))

## You need to use VectorSource before using Corpus
library(tm)
myCorpus <- Corpus(VectorSource(myTable$sentence))
tdm <- TermDocumentMatrix(myCorpus)

inspect(tdm)
#<<TermDocumentMatrix (terms: 8, documents: 4)>>
#Non-/sparse entries: 8/24
#Sparsity           : 75%
#Maximal term length: 6
#Weighting          : term frequency (tf)
#Sample             :
#         Docs
#Terms   1 2 3 4
#doe     0 1 0 0
#good    0 0 0 1
#john    0 1 0 0
#luck    0 0 0 1
#name    0 1 0 0
#thank   0 0 1 0
#window  1 0 0 0
#you     0 0 1 0