R: Reverse Elements (original) (raw)

rev {base} R Documentation

Description

rev provides a reversed version of its argument. It is generic function with a default method for vectors and one for[dendrogram](../../stats/html/dendrogram.html)s.

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](../../base/help/sort.html)(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.

See Also

[seq](../../base/help/seq.html), [sort](../../base/help/sort.html).

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

[Package _base_ version 4.6.0 Index]