rev
Reverse Elements
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).
- Keywords
- manip
Usage
rev(x)Arguments
- x
a vector or another object for which reversal is defined.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
See Also
Examples
library(base)
# 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
# }
Community examples
# My Favourite Animals animals_ls = list(animals = c("Dog", "Elephant", "T-Rex"), intuitive_size = c("Small", "Medium", "Huge"), speed_in_km = c(55,40,40)) animals_ls # My Favourite Animals in reversed order reversed_animals_ls = rev(animals_ls) # Is it the same? identical(animals_ls, reversed_animals_ls) identical(animals_ls, animals_ls)