bit_sort_unique: bit sort unique

In bit: Classes and Methods for Fast Memory-Efficient Boolean Selections

bit sort unique

Description

fast combination of sort and unique for integers

Usage

bit_sort_unique(
  x,
  decreasing = FALSE,
  na.last = NA,
  has.dup = TRUE,
  range_na = NULL
)

Arguments

x	an integer vector
decreasing	FALSE (ascending) or TRUE (descending)
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
range_na	NULL calls range_na, optionally the result of range_na can be given here to avoid calling it again

Details

determines the range of the integers and checks if the density justifies use of a bit vector; if yes, creates the result using a bit vector; if no, falls back to sort(unique())

Value

a sorted unique integer vector

See Also

sort, unique, bit_sort, bit_unique

Examples

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

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

## End(Not run) 

bit documentation built on Sept. 20, 2024, 5:08 p.m.