Remove Rows with Non-Numeric Characters in R (Example)

This tutorial demonstrates how to drop data frame rows with non-numeric characters in a certain column in the R programming language.

Table of contents:

Let’s just jump right in!

Creation of Example Data

First, let’s create some example data:

data <- data.frame(x1 = c(1:3, "x", 2:1, "y", "x"),  # Create example data frame
                   x2 = 18:11)
data                                                 # Print example data frame

Table 1 illustrates the output of the RStudio console that has been returned after executing the previous R code and shows that the example data is made up of eight rows and two columns.

Example: Keep Only Rows with Numbers in Certain Column Using as.numeric() & is.na() Functions

This example illustrates how to delete all rows where a specific column contains non-numeric values.

For this task, we can apply the as.numeric and is.na functions as shown below:

data_new <- data[!is.na(as.numeric(data$x1)), ]      # Delete rows
data_new                                             # Print data frame subset

As shown in Table 2, we have created a new data frame subset by executing the previous R programming code. This subset contains only those rows where the column x1 contained numeric values.

Note that the previous R code also returns the warning message “In `[.data.frame`(data, !is.na(as.numeric(data$x1)), ) : NAs introduced by coercion“. That is because the as.numeric function converts non-numeric values to NA.

Video, Further Resources & Summary

I have recently published a video on my YouTube channel, which illustrates the contents of this article. You can find the video below.

Furthermore, you might want to read the related articles on my website.

• Remove Rows with NA in R Data Frame
• Remove Characters Before or After Point in String in R
• Remove Bottom N Rows from Data Frame
• Remove Rows with NA Using dplyr Package
• All R Programming Tutorials

You have learned in this article how to remove data frame rows with non-numeric characters in a particular column in R programming. Please let me know in the comments below, in case you have further comments or questions.