# Change Number of Decimal Places on Axis Tick Labels of Plot in R (2 Examples)

In this article, Iâ€™ll explain how to **modify the number of decimals on the axis tick labels of a plot** in the R programming language.

The content of the article looks as follows:

Letâ€™s dive into itâ€¦

## Creation of Example Data

Have a look at the following example data.

data <- data.frame(x = seq(0.5, 1, 0.1), # Create example data frame y = c(5, 2, 9, 7, 5, 9)) data # Print example data frame

Table 1 shows the structure of our example data: It contains six rows and two numerical variables.

## Example 1: Change Number of Axis Label Decimals in Base R Plot

In Example 1, Iâ€™ll explain how to adjust the decimal places on axis tick labels of a Base R graphic.

Letâ€™s first draw a Base R plot with default axis settings:

plot(data) # Draw Base R plot with default decimals

As shown in Figure 1, we have plotted a Base R scatterplot with only one decimal place on the x-axis by running the previous R syntax.

If we want to change the number of decimal places, we first have to specify the axis positions at which the new labels should be added:

my_label_positions <- seq(min(data$x), # Specify axis positions of labels max(data$x), length = 6) my_label_positions # Print axis positions of labels # [1] 0.5 0.6 0.7 0.8 0.9 1.0

Next, we can use the sprintf function to create a character vector containing our axis tick labels with a different number of decimal places:

my_labels <- sprintf(my_label_positions, # Specify axis labels fmt = '%#.3f') my_labels # Print axis labels # [1] "0.500" "0.600" "0.700" "0.800" "0.900" "1.000"

Finally, we can use the axis function to manually add our new axis tick labels to our plot:

plot(data, # Draw Base R plot without x-axis xaxt = "n") axis(1, # Manually add axis tick labels at = my_label_positions, labels = my_labels)

After running the previous R syntax the Base R scatterplot with manually specified decimal places on the x-axis shown in Figure 2 has been created.

## Example 2: Change Number of Axis Label Decimals in ggplot2 Plot

In Example 2, Iâ€™ll explain how to change the number of decimals in ggplot2 graphs.

First, we need to install and load the ggplot2 package:

install.packages("ggplot2") # Install ggplot2 package library("ggplot2") # Load ggplot2 package

In the next step, we can create a default ggplot2 plot as shown below:

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

As shown in Figure 3, the previous R code has created a ggplot2 scatterplot with a default number of digits after the decimal point.

In order to modify the decimal places on our axis labels, we need to install and load the scales package.

install.packages("scales") # Install scales package library("scales") # Load scales

Now, we can apply the number_format function and the to specify the accuracy argument to specify a certain accuracy of our axis tick labels.

Note that the following R syntax uses the scale_x_continuous function to change the x-axis values. If we would like to adjust the y-axis, we would have to use the scale_y_continuous function instead.

However, letâ€™s draw our graphic:

ggp + # Modify decimal places on ggplot2 plot axis scale_x_continuous(labels = number_format(accuracy = 0.001))

Figure 4 reveals the output of the previous code â€“ A ggplot2 scatterplot with more decimal places on the x-axis.

## Video & Further Resources

Have a look at the following video on my YouTube channel. Iâ€™m explaining the R programming codes of this article in the video:

In addition, you might read the other tutorials on my homepage. A selection of tutorials is shown below.

- Change Formatting of Numbers of ggplot2 Plot Axis
- Add X & Y Axis Labels to ggplot2 Plot
- Change Labels of ggplot2 Facet Plot
- Wrap Long Axis Labels of ggplot2 Plot into Multiple Lines
- Draw Plot with Actual Values as Axis Ticks & Labels
- Rotate Axis Labels of Base R Plot
- R Graphics Gallery
- All R Programming Examples

You have learned on this page how to **change the number of decimal places on the axis tick labels of a plot** in the R programming language. If you have additional comments or questions, let me know in the comments section.