Add Minor Tick Marks without Labels to ggplot2 Plot in R (Example)

This tutorial shows how to draw additional minor tick marks without labels in a ggplot2 plot in the R programming language.

Table of contents:

Let’s dive right into the example…

Example Data, Packages & Basic Graph

The data below will be used as a basis for this R programming tutorial.

data <- data.frame(x = 1:6,                # Create example data frame
                   y = c(1, 3, 5, 2, 2, 4))
data                                       # Print example data frame

Table 1 shows that our example data contains six rows and two variables.

In order to draw our data using the ggplot2 package, we also have to install and load ggplot2:

install.packages("ggplot2")                # Install & load ggplot2 package
library("ggplot2")

Next, we can plot our data.

ggp <- ggplot(data, aes(x, y)) +           # Create ggplot2 plot with default axes
  geom_line()
ggp                                        # Draw ggplot2 plot with default axes

As shown in Figure 1, we have managed to create a new ggplot2 plot with default specifications for the minor and major tick marks, as well as for the corresponding grid lines.

Example: Draw ggplot2 Plot with Additional Axis Tick Marks without Labels

The code below demonstrates how to add additional axis tick marks without labels to a ggplot2 graphic.

As a first step, we have to specify the breaks (i.e. the tick marks) that we want to use in our plot. For this, we can use the seq() function as shown below:

my_breaks <- seq(1, 6, by = 0.5)           # Create sequence for new x-axis
#  [1] 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
my_breaks                                  # Print sequence for new x-axis

We may now use this sequence to create a ggplot2 plot with modified axis ticks and grid lines:

ggp +                                      # Draw ggplot2 plot with new x-axis
  scale_x_continuous(breaks = my_breaks)

Figure 2 visualizes the output of the previous R syntax: A ggplot2 plot with additional axis ticks on the x-axis.

However, at this point all the new axis ticks have labels. Let’s change that!

To drop some of the axis labels, we have to create another vector with the same length as our breaks vector. This vector needs to contain the labels that we want to show as well as a blank character for the labels we do not want to show:

my_labels <- sprintf("%.1f", my_breaks)    # Specify blanks for unnecessary labels
#  [1] ""    ""    "2.0" ""    ""    ""    "4.0" ""    ""    ""    "6.0"
my_labels[c(1, 2, 4, 5, 6, 8, 9, 10)] <- ""
my_labels                                  # Print updated labels

Finally, we can draw our plot with additional axis tick marks:

ggp +                                      # Additional minor axis ticks without labels
  scale_x_continuous(breaks = my_breaks,
                     labels = my_labels)

As shown in Figure 3, we have created a ggplot2 graph with additional axis tick marks, but no additional labels.

Note that we could use the same logic to add further axis tick marks on the y-axis.

Video, Further Resources & Summary

I have recently published a video on my YouTube channel, which shows the examples of the present article. You can find the video below:

Furthermore, you could have a look at the other articles on my homepage:

• Adjust Space Between ggplot2 Axis Labels and Plot Area
• Add Individual Text to Each Facet of ggplot2 Plot
• Add Marginal Plot to ggplot2 Scatterplot Using ggExtra Package
• Add Bold & Italic Text to ggplot2 Plot
• Modify Major & Minor Grid Lines of ggplot2 Plot
• Add Text to ggplot2 Plot in R
• Plots in R
• R Programming Tutorials

To summarize: You have learned in this tutorial how to add additional minor tick marks without labels in a ggplot2 graph in the R programming language. Please let me know in the comments section, in case you have additional questions. In addition, don’t forget to subscribe to my email newsletter in order to receive updates on new articles.