[R] Fixed size permutations

[Nick Fankhauser]

I'm using functions to return a matrix of all permutations of a
specified size from a larger list for predictor selection.
For each predictor size I use a seperate function like this:

bag2 <- function(n) {
    rl <- c()
    for (i1 in seq(n)) {
        for (i2 in seq(n)) {
            if (length(unique(c(i1,i2)))==1) {next}
            rl <- cbind(rl,matrix(c(i1,i2)))
        }
    }
    rl
}

bag3 <- function(n) {
    rl <- c()
    for (i1 in seq(n)) {
        for (i2 in seq(n)) {
            for (i3 in seq(n)) {
                if (length(unique(c(i1,i2,i3)))==1) {next}
                rl <- cbind(rl,matrix(c(i1,i2,i3)))
            }
        }
    }
    rl
}

But I think it should be somehow possible in R to use one general
function for all sizes. Can someone help?
I don't exactly know how this kind of permutation is called, maybe this
would help to find a solution.

Nick