funique {collapse}R Documentation

Fast Unique Elements / Rows

Description

funique is a substantially faster alternative to unique. It is generic with a default vector and a data frame methods.

Usage

funique(x, ...)

## Default S3 method:
funique(x, sort = FALSE, method = "auto", ...)

## S3 method for class 'data.frame'
funique(x, cols = NULL, sort = FALSE, method = "auto", ...)

## S3 method for class 'sf'
funique(x, cols = NULL, sort = FALSE, method = "auto", ...)

Arguments

x

a atomic vector or data frame / list of equal-length columns.

sort

logical. TRUE orders the unique elements / rows. FALSE returns unique values in order of first occurrence.

method

an integer or character string specifying the method of computation:

Int. String Description
1 "auto" automatic selection: hash if sort = FALSE else radix.
2 "radix" use radix ordering to determine unique values. Supports sort = FALSE but only for character data.
3 "hash" use index hashing to determine unique values. Supports sort = TRUE but only for atomic vectors (default method).
cols

compute unique rows according to a subset of columns. Columns can be selected using column names, indices, a logical vector or a selector function (e.g. is.character). Note: All columns are returned.

...

arguments passed to radixorderv, e.g. decreasing or na.last. Only applicable if method = "radix".

Details

If x is a data frame / list and all rows are already unique, then x is returned. Otherwise a copy of x with duplicate rows removed is returned. See group for some additional computational details.

The sf method simply ignores the geometry column when determining unique values.

Value

x with duplicate elements/rows removed.

See Also

group, Fast Grouping and Ordering, Collapse Overview.

Examples

funique(mtcars$cyl)
funique(gv(mtcars, c(2,8,9)))
funique(mtcars, cols = c(2,8,9))
[Package collapse version 1.7.6 Index]