Calculate Median of a Vector in R

A vector is a one-dimensional data structure used to store data of the same type in R. Numeric vectors are commonly used to store a sequence of numbers. In this tutorial, we will look at how to get the median value of a numeric vector in R with the help of some examples.

What is the median of a distribution?

Median is a descriptive statistic used as a measure of central tendency in a distribution. It gives a better idea of the center of the distribution (than other estimates such as the mean) particularly if the data has outliers.

The median of a group of values is the middle value, that is, the value that divides the distribution into two equal halves. To manually compute the median, you can sort the values and choose the middle value as the median.

How to get the median of a vector in R?

You can use the R median() function to get the median of values in a vector. Pass the vector as an argument to the function. The following is the syntax –

# median of values in a vector
median(x, na.rm=FALSE)

The following are the arguments that you can give to the median() function in R.

• x – The vector for which you want to compute the median.
• na.rm – (Optional argument) Indicates whether to remove the missing values before computing the median. It is FALSE by default.

The function returns the median of the passed vector.

Examples

Let’s look at some examples of using the above method to compute the median of values in a vector.

Median of a numeric vector

Let’s create a vector of numbers (and without any NA values) and apply the median() function.

# create a vector
vec <- c(1, 3, 2, 4, 5)
# median of values in the vector
median(vec)

Output:

3

We get the median as 3, which is the middle value in the above vector of numbers

What would happen if there are some NA present values in the vector?

Let’s find out.

First, we will create a vector with some NA values and then apply the median() function without any additional arguments.

# create a vector with NA values
vec <- c(1, 3, NA, 2, 4, 5, NA)
# median of values in the vector
median(vec)

Output:

<NA>

You can see that we get NA as the output. This is because comparing anything with NA results in an NA in R.

Median of a vector with NA values

You can pass TRUE to the na.rm parameter of the median() function to exclude missing values when computing the median of a vector.

# create a vector with NA values
vec <- c(1, 3, NA, 2, 4, 5, NA)
# median of values in the vector
median(vec, na.rm = TRUE)

Output:

3

Now we get the median of the values in the above vector as 3.

You might also be interested in –

• Average of Values in an R Vector
• R – Sum of values in a Vector
• Create a Vector in R – With Examples