R: Reverse Elements

rev {base}

R Documentation

Reverse Elements

Description

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).

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.

Examples

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