Replace X-Axis Values in R (Example) | How to Change & Customize Ticks

In this R tutorial you’ll learn how to modify x-axis values manually.

The content of the post looks as follows:

• Creating Example Plot
• Example: Changing X-Axis Values to Letters
• Video & Further Resources

Let’s get started.

Creating Example Plot

Let’s first create an exemplifying graphic in R:

plot(1:5)                       # Create plot in Base R

Figure 1: Plot with Default X-Axis Values.

Figure 1 shows the output of the previous R code: A scatterplot with an x-axis ranging from 1 to 5.

Example: Changing X-Axis Values to Letters

Let’s assume that we want to modify our x-axis ticks so that the currently shown numbers are replaced by upper case letters. Then, we first have to create a graph without any axis values:

plot(1:5,                       # Create plot without x-axis
     xaxt = "n",
     xlab = "My X-Axis")

Figure 2: Plot without X-Axis Values.

Figure 2 shows our plot without axis values.

Now, we can add custom axis values by using the axis function as shown below:

axis(1,                         # Define x-axis manually
     at = 1:5,
     labels = LETTERS[1:5])

Figure 3: Plot with Custom X-Axis Values.

Figure 3 shows our final result: A scatterplot with custom axis values.

Video & Further Resources

Do you need more explanations on the R codes of this article? Then I can recommend to have a look at the following video instruction which I have published on my YouTube channel. I show the R programming syntax of the present tutorial in the video.

Furthermore, you might have a look at the related articles that I have published on my website. I have released numerous tutorials already.

• Remove Axis Values of Plot in Base R
• Rotate Axis Labels of Base R Plot
• axis() Function in R
• Change Formatting of Numbers of ggplot2 Plot Axis
• R Graphics Gallery
• The R Programming Language

In summary: You learned in this tutorial how to change the values on our axis scale in the R programming language. If you have further questions, please let me know in the comments section below.