Find unique pairs of words ignoring their order in two columns in R

Question

I have a data frame that contains duplicated values in two columns.

   dat<-data.frame(V1 = c(\"home\",\"cat\",\"fire\",\"sofa\",\"kitchen\",\"sofa\"), 
          


        

Answer 1

library(igraph)
myList = lapply(split(dat, dat$V3), function(x) {  # Split the data by third column
    g1 = graph.data.frame(x, directed = FALSE)  # create undirected graph
    g2 = simplify(g1, remove.multiple = TRUE)  # remove duplicates (same pairs)
    get.edgelist(g2)   #Convert to list of pairs
})

# Add the date back and then combine rows
do.call(rbind, lapply(names(myList), function(nm) data.frame(myList[[nm]], nm)))
#       X1    X2    nm
#1    home   cat date1
#2    fire water date2
#3    sofa    TV date3
#4 kitchen knife date4

Answer 2

dat[!duplicated(t(apply(dat, 1, sort))),]

Using apply and sort will loop through each row and sort. We can then transpose the output and determine duplicates using duplicated. Because duplicated returns a boolean we then subset all rows in dat where duplicated = FALSE.