sets
Set Operations
Performs set union, intersection, (asymmetric!) difference, equality and membership on two vectors.
 Keywords
 misc
Usage
union(x, y)
intersect(x, y)
setdiff(x, y)
setequal(x, y)
is.element(el, set)
Arguments
 x, y, el, set
 vectors (of the same mode) containing a sequence of items (conceptually) with no duplicated values.
Details
Each of union
, intersect
, setdiff
and
setequal
will discard any duplicated values in the arguments,
and they apply as.vector
to their arguments (and so
in particular coerce factors to character vectors).
is.element(x, y)
is identical to x %in% y
.
Value

A vector of the same mode as x or y for
setdiff and intersect, respectively, and
of a common mode for union.A logical scalar for setequal and a logical of the same
length as x for is.element.
See Also
‘plotmath’ for the use of union
and
intersect
in plot annotation.
Examples
library(base)
(x < c(sort(sample(1:20, 9)), NA))
(y < c(sort(sample(3:23, 7)), NA))
union(x, y)
intersect(x, y)
setdiff(x, y)
setdiff(y, x)
setequal(x, y)
## True for all possible x & y :
setequal( union(x, y),
c(setdiff(x, y), intersect(x, y), setdiff(y, x)))
is.element(x, y) # length 10
is.element(y, x) # length 8
Community examples
example for [LinkedIn Learning Video](https://linkedinlearning.pxf.io/rweekly_equalIn) ```r # create two vectors to demonstrate vectA < c(1:10) vectB < c(10:15) # is vectA == vectB ? setequal(vectA, vectB) # what parts of vectA are in vectB? is.element(vectA, vectB) # what parts of vectB are in vectA? is.element(vectB, vectA) # equivalent notation for is.element(vectA, vectB) vectA %in% vectB # elements in sets do not need to be sorted vectBRandom < sample(vectB, length(vectB)) vectBRandom intersect(vectA, vectBRandom) setdiff(vectBRandom, vectA) setequal(vectB, vectBRandom) ```
Example files from [LinkedIn Learning, R for Data Science, Lunchbreak Lessons](https://linkedinlearning.pxf.io/Rweekly_setsUnionInterDiff). ```r # create two vectors to demonstrate vectA < c(1:10) vectB < c(10:15) # union  combine the vectors  removing duplicates union(vectA, vectB) # intersect  find the overlap intersect(vectA, vectB) # what is unique about vectA? setdiff(vectA, vectB) # what is unique about vectB? setdiff(vectB, vectA) # elements in sets do not need to be sorted vectBRandom < sample(vectB, length(vectB)) vectBRandom intersect(vectA, vectBRandom) setdiff(vectBRandom, vectA) setequal(vectB, vectBRandom) ```