bit: bit_sort – R documentation

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bit

bit_sort

bit sort

Description

fast sorting of integers

Usage

bit_sort(x, decreasing = FALSE, na.last = NA, has.dup = TRUE)

Arguments

`x`	an integer vector
`decreasing`	(currently only `FALSE` is supported)
`na.last`	`NA` removes NAs, `FALSE` puts NAs at the beginning, `TRUE` puts NAs at the end
`has.dup`	TRUE (the default) assumes that `x` might have duplicates, set to `FALSE` if duplicates are impossible

Details

determines the range of the integers and checks if the density justifies use of a bit vector; if yes, sorts the first occurences of each integer in the range using a bit vector, sorts the rest and merges; if no, falls back to quicksort.

Value

a sorted vector

Examples

bit_sort(c(2L,1L,NA,NA,1L,2L))
bit_sort(c(2L,1L,NA,NA,1L,2L), na.last=FALSE)
bit_sort(c(2L,1L,NA,NA,1L,2L), na.last=TRUE)

## Not run: 
x <- sample(1e7, replace=TRUE)
system.time(bit_sort(x))
system.time(sort(x))

## End(Not run)

bit

Classes and Methods for Fast Memory-Efficient Boolean Selections

v4.0.4

GPL-2 | GPL-3

Authors

Jens Oehlschlägel [aut, cre], Brian Ripley [ctb]

Initial release

2020-08-03