Test for Equality of All Vector Elements in R

In this article, we will test the equality of all vector elements in R programming language.

Method 1: Using variance

We can say that all vector elements are equal if the variance is zero. We can find variance by using the var() function

Syntax:

var(vector)==0

where vector is an input vector

This function returns true if all elements are the same, otherwise false.

Example: R program to check all elements in a vector equality

R

# consider a vector with same elements
vec1 = c(7, 7, 7, 7, 7, 7, 7)

print(var(vec1) == 0)

# consider a vector with different elements
vec2 = c(17, 27, 37, 47, 57, 7, 7)

print(var(vec2) == 0)

Output:

[1] TRUE
[1] FALSE

Method 2: Using length()  and unique()  function

By using unique function if all the elements are the same then the length is 1 so by this way if the length is 1, we can say all elements in a vector are equal.

Syntax:

length(unique(vector))==1

• length() is used to find the length of unique vector
• unique() is used to get the unique values in a vector

If all elements are the same it returns true, otherwise false

Example: R program to test the equality of all elements in a vector

R

# consider a vector with same elements
vec1 = c(7, 7, 7, 7, 7, 7, 7)

print(length(unique(vec1)) == 1)

# consider a vector with different elements
vec2 = c(17, 27, 37, 47, 57, 7, 7)

print(length(unique(vec2)) == 1)

Output:

[1] TRUE
[1] FALSE