How to check missing values in R dataframe ?

In this article, we are going to see how to find out the missing values in the data frame in R Programming Language.

Approach:

Step 1: Create DataFrame.

Let us first create a data frame with some missing values and then demonstrate with an example how to find the missing values.

R

data <- data.frame(x1 = c(NA, 5, 6, 8, 9),
                        x2 = c(2, 4, NA, NA, 1),
                        x3 = c(3,6,7,0,3),
                        x4 = c("Hello", "value",
                               NA, "geeksforgeeks", NA))

display(data)

Output:

We have created a data frame with some missing values (NA).

Step 2: Now to check the missing values we are using is.na() function in R and print out the number of missing items in the data frame as shown below.

Syntax: is.na()

Parameter: x: data frame

Example 1:

In this example, we have first created data with some missing values and then found the missing value in particular columns x1,×2, x3, and x4 respectively using the above function.

R

data <- data.frame(x1 = c(NA, 5, 6, 8, 9),
                        x2 = c(2, 4, NA, NA, 1),
                        x3 = c(3,6,7,0,3),
                        x4 = c("Hello", "value",
                               NA, "geeksforgeeks", NA))

data

# to find out the missing value
which(is.na(data$x1))
which(is.na(data$x2))
which(is.na(data$x3))
which(is.na(data$x4))

Output:

Print the variables which have missing values and the number of missing values.

Example 2: 

Let’s find the number of missing values using a different approach, here in this example, we have created data with missing values and then find the number of missing values in the data.

R

Name <- c("John", "Sunny", NA)
Age <- c(31, 18, NA)
number<- c("0", "1", "2")

data <- data.frame(Name, Sex, number)

display(data)

Output:

We have a data frame, and we have to find the number of missing values in this data frame.

R

Name <- c("John", "Sunny", NA)
Age <- c(31, 18, NA)
number<- c("0", "1", "2")

data <- data.frame(Name, Sex, number)
sum(is.na(data))

Output: