Calculate word co-occurance matrix in r

Question

I would like to calculate a word co-occurance matrix in R. I have the following data frame of sentences -

dat <- as.data.frame(\"The boy is tall.\", header =         


        

Answer 1

library(tm)
library(dplyr)
dat      <- as.data.frame("The boy is tall.", header = F, stringsAsFactors = F)
dat[2,1] <- c("The girl is short.")
dat[3,1] <- c("The tall boy and the short girl are friends.")

ds  <- Corpus(DataframeSource(dat))
dtm <- DocumentTermMatrix(ds, control=list(wordLengths=c(1,Inf)))

X         <- inspect(dtm)
out       <- crossprod(X)  # Same as: t(X) %*% X
diag(out) <- 0             # rm own-word occurences
out

        Terms
Terms    boy friend girl short tall the
  boy      0      1    1     1    2   2
  friend   1      0    1     1    1   1
  girl     1      1    0     2    1   2
  short    1      1    2     0    1   2
  tall     2      1    1     1    0   2
  the      2      1    2     2    2   0

You may also want to remove stop words like "the", i.e.

ds <- tm_map(ds, stripWhitespace)
ds <- tm_map(ds, removePunctuation)
ds <- tm_map(ds, stemDocument)
ds <- tm_map(ds, removeWords, c("the", stopwords("english")))
ds <- tm_map(ds, removeWords, c("the", stopwords("spanish")))