Re: [R] Combinations of values in two columns

Hi, You may try: dat1 <- read.table(text=" Friend1,Friend2 A,B A,C B,A C,D",sep=",",header=TRUE,stringsAsFactors=FALSE) indx <- as.vector(outer(unique(dat1[,1]),unique(dat1[,2]),paste)) res <- cbind(setNames(read.table(text=indx,sep="",header=FALSE,stringsAsFactors=FALSE),paste0("Friend",1:2)),

Re: [R] Combinations of values in two columns

Hi Thomas, It depends whether you'd like to include all levels of each column in every column. For including all values you could try something like this: isAllDifferent <- function(z) !any(duplicated(z)) myData <- data.frame(Friend1=c("a", "a", "b", "c"), Friend2=c("b", "c

Re: [R] Combinations of values in two columns

You could use the data.table package require(data.table) DT <- data.table(Friend1 = sample(LETTERS, 10, replace = TRUE), Friend2 = sample(LETTERS, 10, replace = TRUE), Indicator = 1) ALL <- data.table(unique(expand.grid(DT))) setkey(ALL) OTHERS <- ALL[!DT] OTHERS[, Indicator := 0] RESULT <- rbi