Find backward duplicates in a data frame

Hi,May be:

fun1 <- function(dat){
indx <- apply(dat,1,function(x) {
??? ??? any(x==sort(x))| !any(as.character(interaction(dat,sep="")) %in% paste(sort(x),collapse=""))
??? ??? })
dat[indx,]
}

test1 <- rbind(test,data.frame(a="F",u="E"))
fun1(test)
fun1(test1)




A.K.

Hello,

I am looking for a method to eliminate rows dupblicates in a backwards
manner, for instance:
I want to keep A B but not B A (see my data.frame test).
Thanks
Hermann

test

? a u
1 A B
2 A C
3 B A
4 B F
5 C A
6 D W

dput (test)

structure(list(a = structure(c(1L, 1L, 2L, 2L, 3L, 4L), .Label = c("A",
"B", "C", "D"), class = "factor"), u = structure(c(2L, 3L, 1L,
4L, 1L, 5L), .Label = c("A", "B", "C", "F", "W"), class = "factor")),
.Names = c("a",
"u"), row.names = c(NA, -6L), class = "data.frame")

??? [[alternative HTML version deleted]]

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