rev provides a reversed version of its argument. It is generic function with a default method for vectors and one for dendrograms. Note that this is no longer needed (nor efficient) for obtaining vectors sorted into descending order, since that is now rather more directly achievable by sort(x, decreasing = TRUE).
rev(x)| Parameter | Description |
|---|---|
x |
a vector or another object for which reversal is defined. |
# NOT RUN {
x <- c(1:5, 5:3)
## sort into descending order; first more efficiently:
stopifnot(sort(x, decreasing = TRUE) == rev(sort(x)))
stopifnot(rev(1:7) == 7:1) #- don't need 'rev' here
# }