List distinct values in a vector in R

In this article, we will discuss how to display distinct values in a vector in R Programming Language.

Method 1: Using unique()

For this, the vector from which distinct elements are to be extracted is passed to the unique() function. The result will give all distinct values in a vector. 

Syntax:

unique(vector_name)

Where, vector_name is the input vector.

Example 1:

R

# vector data
a=c(1,2,3,4,1,2,5.9,9.0,9.0,45,78)

# display vector
print(a)

# unique values
print(unique(a))

Output:

[1]  1.0  2.0  3.0  4.0  1.0  2.0  5.9  9.0  9.0 45.0 78.0

[1]  1.0  2.0  3.0  4.0  5.9  9.0 45.0 78.0

Example 2:

R

# vector data
a=c("manoj","sravan","tripura","manoj",
    "bala","sailaja","soundarya","sravan")

# display vector
print(a)

# unique values
print("Distinct values are :")
print(unique(a))

Output:

Example 3:

R

# vector data
a=c(FALSE,TRUE,FALSE,TRUE)

# display vector
print(a)

# unique values
print("Distinct values are :")
print(unique(a))

Output:

Method 2: Using duplicated()

By using this method we can get duplicate values. So, if we want to get unique values, we can implement this function along with ! Operator. This will do exactly the reverse of the duplicated() function.

Syntax:

!duplicated(vector_data)

This will return boolean values.

In order to return actual values, we can use index operator — []

Syntax:

vector_name[!duplicated(vector_name)]

Example 1:

R

# create a vector with numeric
# elements
x=c(1,2,3,4,5,6,7,8,1,2,3,4,5,3,4)

# display a vector
print(x)

# get distinct value s using
# duplicated function
print(x[!duplicated(x)])

Output:

 [1] 1 2 3 4 5 6 7 8 1 2 3 4 5 3 4
[1] 1 2 3 4 5 6 7 8

Example 2:

R

# create a vector with character  elements
x=c("manoj","sravya","uha lakshmi","sravya",
    "tapaswi","manoj","lakshmi")

# display a vector
print(x)

# get distinct value s using duplicated
# function
print(x[!duplicated(x)])

Output:

Example 3:

R

# create a vector with elements
x=c("manoj","sravya","uha lakshmi",
    "sravya","tapaswi","manoj","lakshmi",
    1:20,12,34,56,23,11,7,8,9,0)

# display a vector
print(x)

# get distinct value s using duplicated
# function
print(x[!duplicated(x)])

Output: