na_if R Function of dplyr Package (2 Examples) | Convert Value to NA

In this article you’ll learn how to replace NA values with the na_if function of the dplyr add-on package in the R programming language.

The article will contain this:

• Example 1: Apply na_if Function to Vector
• Example 2: Apply na_if Function to Data Frame or Tibble
• Video, Further Resources & Summary

Let’s jump right to the examples.

Example 1: Apply na_if Function to Vector

As a first step, we need to install and load the dplyr package to R:

install.packages("dplyr")         # Install dplyr add-on package
library("dplyr")                  # Load dplyr add-on package

Furthermore, we have to create an example vector, to which we can apply the na_if function later on:

x <- 1:10                         # Create example vector
x                                 # Print example vector
# 1  2  3  4  5  6  7  8  9 10

Now, we can use the na_if function to replace a certain value of our example vector with NA:

na_if(x, 5)                       # Apply na_if to vector
# 1  2  3  4 NA  6  7  8  9 10

As you can see based on the previous R code and the output of the RStudio console, we replaced the value 5 of our vector with NA.

Example 2: Apply na_if Function to Data Frame or Tibble

We can also use the na_if command to replace certain values of a data frame or tibble with NA. Let’s create an example data frame first:

data <- data.frame(x1 = 1:5,      # Create example data
                   x2 = 5:9)
data                              # Print example data
#   x1 x2
# 1  1  5
# 2  2  6
# 3  3  7
# 4  4  8
# 5  5  9

Our data frame contains five rows and two numeric variables. Now, we can apply the na_if function to this data frame as shown below:

na_if(data, 5)                    # Apply na_if to data frame
#   x1 x2
# 1  1 NA
# 2  2  6
# 3  3  7
# 4  4  8
# 5 NA  9

The previous R syntax replaced each 5 in our data set with NA.

Video, Further Resources & Summary

Have a look at the following video that I have published on my YouTube channel. I’m explaining further functions of the dplyr package in the video:

Furthermore, I can recommend to have a look at some of the other articles of my website. You can find some tutorials here:

• Replace NA with 0
• Replace NA with Last Observed Value
• str_replace_na Function in R
• Introduction to dplyr
• R Functions List (+ Examples)
• The R Programming Language

In summary: In this tutorial you learned how to convert values to NA with the dplyr package in the R programming language. If you have further questions or comments, please let me know in the comments below.