data.table: setops – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

setops

Set operations for data tables

Description

Similar to base R set functions, union, intersect, setdiff and setequal but for data.tables. Additional all argument controls how duplicated rows are handled. Functions fintersect, setdiff (MINUS or EXCEPT in SQL) and funion are meant to provide functionality of corresponding SQL operators. Unlike SQL, data.table functions will retain row order.

Usage

fintersect(x, y, all = FALSE)
fsetdiff(x, y, all = FALSE)
funion(x, y, all = FALSE)
fsetequal(x, y, all = TRUE)

Arguments

x, y

data.tables.

all

Logical. Default is FALSE and removes duplicate rows on the result. When TRUE, if there are xn copies of a particular row in x and yn copies of the same row in y, then:

fintersect will return min(xn, yn) copies of that row.
fsetdiff will return max(0, xn-yn) copies of that row.
funion will return xn+yn copies of that row.
fsetequal will return FALSE unless xn == yn.

Details

bit64::integer64 columns are supported but not complex and list, except for funion.

Value

A data.table in case of fintersect, funion and fsetdiff. Logical TRUE or FALSE for fsetequal.

References

https://db.apache.org/derby/papers/Intersect-design.html

Examples

x = data.table(c(1,2,2,2,3,4,4))
x2 = data.table(c(1,2,3,4)) # same set of rows as x
y = data.table(c(2,3,4,4,4,5))
fintersect(x, y)            # intersect
fintersect(x, y, all=TRUE)  # intersect all
fsetdiff(x, y)              # except
fsetdiff(x, y, all=TRUE)    # except all
funion(x, y)                # union
funion(x, y, all=TRUE)      # union all
fsetequal(x, x2, all=FALSE) # setequal
fsetequal(x, x2)            # setequal all

data.table

Extension of `data.frame`

v1.14.0

MPL-2.0 | file LICENSE

Authors

Matt Dowle [aut, cre], Arun Srinivasan [aut], Jan Gorecki [ctb], Michael Chirico [ctb], Pasha Stetsenko [ctb], Tom Short [ctb], Steve Lianoglou [ctb], Eduard Antonyan [ctb], Markus Bonsch [ctb], Hugh Parsonage [ctb], Scott Ritchie [ctb], Kun Ren [ctb], Xianying Tan [ctb], Rick Saporta [ctb], Otto Seiskari [ctb], Xianghui Dong [ctb], Michel Lang [ctb], Watal Iwasaki [ctb], Seth Wenchel [ctb], Karl Broman [ctb], Tobias Schmidt [ctb], David Arenburg [ctb], Ethan Smith [ctb], Francois Cocquemas [ctb], Matthieu Gomez [ctb], Philippe Chataignon [ctb], Nello Blaser [ctb], Dmitry Selivanov [ctb], Andrey Riabushenko [ctb], Cheng Lee [ctb], Declan Groves [ctb], Daniel Possenriede [ctb], Felipe Parages [ctb], Denes Toth [ctb], Mus Yaramaz-David [ctb], Ayappan Perumal [ctb], James Sams [ctb], Martin Morgan [ctb], Michael Quinn [ctb], @javrucebo [ctb], @marc-outins [ctb], Roy Storey [ctb], Manish Saraswat [ctb], Morgan Jacob [ctb], Michael Schubmehl [ctb], Davis Vaughan [ctb], Toby Hocking [ctb], Leonardo Silvestri [ctb], Tyson Barrett [ctb], Jim Hester [ctb], Anthony Damico [ctb], Sebastian Freundt [ctb], David Simons [ctb], Elliott Sales de Andrade [ctb], Cole Miller [ctb], Jens Peder Meldgaard [ctb], Vaclav Tlapak [ctb], Kevin Ushey [ctb], Dirk Eddelbuettel [ctb], Ben Schwen [ctb]

Initial release