# How to find the union of three vectors in R?

The union function in base R helps us to find the union of two vectors but if we have three vectors then the union cannot be directly created. For this purpose, we need to use union function twice. For example, if we have three vectors defined as x, y, and z then the union of these vectors can be found by using the command union(x,union(y,z)).

## Example1

Live Demo

> x1<-1:5
> y1<-6:10
> z1<-11:15
> union(x1,union(y1,z1))

## Output

[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

## Example2

Live Demo

> x2<-rpois(100,10)
> x2

## Output

[1] 13 6 16 11 9 11 3 15 12 12 13 9 13 11 17 12 17 6 8 10 16 13 6 9 16
[26] 5 8 14 7 14 7 13 9 9 14 13 12 8 9 10 10 9 8 10 10 9 12 9 7 11
[51] 10 12 15 11 10 13 9 7 12 9 13 13 14 7 11 12 12 11 11 11 10 6 9 11 4
[76] 9 7 10 6 11 18 12 9 9 12 11 10 4 8 9 7 4 8 10 7 13 10 11 11 10

## Example

Live Demo

> y2<-rpois(100,8)
> y2

## Output

[1] 13 5 13 12 4 6 6 13 6 9 9 6 12 3 7 7 8 9 7 4 11 9 6 13 5
[26] 4 11 9 13 11 9 15 10 7 6 7 16 9 9 7 5 7 7 11 6 4 11 7 9 2
[51] 6 8 6 8 6 9 13 7 11 7 11 7 9 7 9 8 5 7 6 16 1 8 7 5 8
[76] 7 4 14 8 7 6 4 7 9 13 11 9 11 6 6 9 7 8 8 9 12 2 8 6 11

## Example

Live Demo

> z2<-rpois(100,5)
> z2

## Output

[1] 5 7 3 4 3 4 10 3 2 4 4 5 7 7 4 4 4 5 7 3 2 7 1 5 5
[26] 3 5 6 5 4 4 1 7 6 5 7 6 6 4 4 7 5 4 1 3 5 1 4 5 5
[51] 6 1 4 1 7 1 4 4 7 5 6 5 4 4 5 5 2 4 1 6 0 2 3 7 6
[76] 6 4 4 8 7 3 11 5 3 2 2 4 5 4 5 5 5 1 6 4 2 8 6 4 5

## Example

> union(x2,union(y2,z2))

## Output

[1] 13 6 16 11 9 3 15 12 17 8 10 5 14 7 4 18 2 1 0

## Example

> x3<-rpois(100,1)
> x3

## Output

[1] 2 2 0 0 2 0 2 1 0 1 1 2 1 0 1 2 0 0 0 2 1 3 1 2 1 0 1 0 0 1 2 0 2 0 1 1 2
[38] 3 0 2 1 0 0 4 2 2 0 2 2 1 2 1 1 0 0 1 1 3 2 0 4 2 0 2 4 1 0 0 0 0 0 0 0 1
[75] 0 2 1 1 2 3 2 0 1 0 2 1 0 0 1 2 0 1 0 0 0 1 2 1 0 1

## Example

> y3<-rpois(100,2)
> y3

## Output

[1] 5 2 0 2 0 2 1 3 1 2 0 5 1 0 0 2 2 0 1 2 2 2 3 0 2 3 1 0 3 4 3 3 1 0 2 1 3
[38] 1 3 3 5 0 1 2 1 4 5 4 2 2 2 3 3 1 4 5 2 0 2 1 3 3 3 3 1 1 2 2 1 2 3 2 3 3
[75] 2 0 2 4 3 1 3 2 2 2 2 4 1 1 1 0 3 3 4 4 1 1 2 3 1 1

## Example

> z3<-rpois(100,5)
> z3

## Output

 [1] 4 8 4 6 7 6 4 3 3 5 3 7 4 7 7 1 4 6 9 3 7 8 4 4 2
[26] 6 9 6 4 6 2 5 4 10 6 4 6 5 4 4 3 5 1 4 3 2 8 6 4 5
[51] 11 8 5 7 2 3 4 4 3 0 5 6 8 4 6 8 4 6 2 8 1 5 7 4 5
[76] 8 6 5 3 7 3 3 4 8 3 7 7 4 3 7 3 8 3 4 7 4 4 6 9 6

## Example

> union(x3,union(y3,z3))

## Output

[1] 2 0 1 3 4 5 8 6 7 9 10 11

## Example4

Live Demo

> x4<-round(runif(120,1,2),0)
> x4

## Output

[1] 2 1 2 2 1 1 1 1 2 1 1 1 2 2 2 2 1 2 1 2 1 1 2 1 2 2 2 1 1 1 1 2 2 2 1 1 2
[38] 2 1 1 2 1 1 2 1 1 1 1 1 2 2 1 2 1 1 2 2 2 2 2 1 2 1 1 1 2 2 2 2 2 1 2 2 2
[75] 2 2 1 2 1 2 2 1 2 2 1 1 2 1 2 1 1 1 1 1 1 2 2 1 1 1 2 2 1 1 2 2 1 2 2 2 1
[112] 1 2 2 1 1 1 2 1 1

## Example

Live Demo

> y4<-round(runif(120,1,5),0)
> y4

## Output

[1] 2 3 5 4 3 5 5 5 4 3 3 4 4 1 4 3 2 4 2 2 4 5 4 5 4 4 3 5 5 2 2 4 2 1 3 2 1
[38] 5 2 4 5 4 3 2 3 3 4 2 1 4 3 2 2 3 2 4 3 4 3 4 4 1 4 2 4 2 3 1 4 2 4 1 5 3
[75] 4 2 5 5 4 4 2 4 4 4 2 5 5 2 2 3 5 3 5 2 4 2 2 4 2 1 3 2 3 3 3 3 2 2 1 4 3
[112] 5 4 1 4 2 3 4 4 4

## Example

Live Demo

> z4<-round(runif(120,2,10),0)
> z4

## Output

[1] 8 8 4 5 9 6 6 8 4 6 3 6 5 9 3 9 3 6 10 7 9 9 8 2 4
[26] 7 6 10 6 6 3 4 8 4 8 5 6 8 5 8 10 9 7 10 3 5 7 8 10 4
[51] 9 4 8 3 9 8 9 3 4 10 6 10 9 7 6 7 7 9 2 10 10 6 4 9 6
[76] 8 7 5 9 6 8 8 6 5 6 9 7 2 7 4 4 3 8 8 6 6 4 9 2 10
[101] 5 9 5 7 10 7 3 9 4 6 6 8 5 4 7 5 5 9 5 2

## Example

> union(x4,union(y4,z4))
[1] 2 1 3 5 4 8 9 6 10 7

## Example5

Live Demo

> x5<-round(rnorm(120,1,0.5),0)
> x5

## Output

[1] 1 1 1 2 1 1 1 1 0 2 1 2 0 1 1 1 1 2 1 1 1 1 1 1 1
[26] 0 1 2 1 2 0 1 1 1 1 1 0 0 2 1 1 1 2 1 2 1 1 1 1 1
[51] -1 1 2 0 1 1 1 0 1 1 2 1 1 1 1 1 0 1 1 2 1 0 0 0 2
[76] 1 1 1 1 0 1 1 1 1 2 1 1 1 0 1 1 0 1 0 0 1 1 1 1 1
[101] 1 0 1 0 1 2 0 2 1 1 1 1 1 1 1 1 1 1 1 1

## Example

Live Demo

> y5<-round(rnorm(120,5,0.25),0)
> y5

## Output

[1] 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6 5 5 5 5 5 6 5 5 5 5 5 5 6 5 5 5 5 5 5 5 5
[38] 5 5 5 5 5 6 6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
[75] 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6
[112] 5 5 5 5 5 5 5 5 5

## Example

Live Demo

> z5<-round(rnorm(120,5,3),0)
> z5

## Output

[1] 9 4 5 6 6 8 5 8 8 5 8 0 5 2 6 5 0 4 6 7 0 7 10 8 8
[26] 6 10 2 4 1 6 9 4 2 6 7 5 2 10 5 5 -2 6 0 5 5 8 7 1 4
[51] 5 9 0 7 4 10 4 4 2 6 2 3 6 7 8 8 8 5 1 7 4 5 8 6 2
[76] 7 0 1 7 9 1 6 5 8 2 10 8 3 3 1 6 4 5 6 11 8 8 3 10 4
[101] 7 1 5 4 2 2 3 6 8 8 7 3 1 8 7 4 4 4 3 5

## Example

> union(x5,union(y5,z5))

## Output

[1] 1 2 0 -1 5 6 9 4 8 7 10 -2 3 11