Implement the sort and order methods for data.frame and matrix, sorting it in lexicographic order.

Description

These function return a data frame sorted in lexcographic order or a permutation that will rearrange it into lexicographic order: first by the first column, ties broken by the second, remaining ties by the third, etc..

Usage

order(..., na.last = TRUE, decreasing = FALSE)

## Default S3 method:
order(..., na.last = TRUE, decreasing = FALSE)

## S3 method for class 'data.frame'
order(..., na.last = TRUE, decreasing = FALSE)

## S3 method for class 'matrix'
order(..., na.last = TRUE, decreasing = FALSE)

## S3 method for class 'data.frame'
sort(x, decreasing = FALSE, ...)

Arguments

Value

For sort, a data frame, sorted lexicographically. For order, a permutation I (of a vector 1:nrow(x)) such that x[I,,drop=FALSE] equals x ordered lexicographically.

See Also

data.frame, sort, order, matrix

Examples

data(iris)

head(iris)

head(order(iris))

head(sort(iris))

stopifnot(identical(sort(iris),iris[order(iris),]))