Label BoxPlot in R

R is equipped with many functions for different types of graphs and plots. Such plots are very useful and can provide good insights into the data.

The BoxPlot is a unique and useful graph type. It allows us to study the distribution of data and identify different trends in the dataset. We can use it for comparison between different groups as well.

In R, we generally use the boxplot() function to create such graphs but we can also make use of the geom_boxplot() function with the ggplot() function to create boxplots and there are some other methods available as well.

The following example shows a simple boxplot of three sample distributions using the boxplot() function.

v1 <- c(1,2,3,4)
v2 <- c(3,4,5,6)
v3 <- c(5,6,7,8)
boxplot(v1,v2,v3)

Simple Boxplot in R

We can also label the graph properly using the right parameters. The xlab parameter labels the x-axis and ylab parameter labels the y axis. The main parameter sets the title of the graph. We can label the different groups present in the plot using the names parameter. The following code and graph will show the use of all these parameters.

boxplot(v1,v2,v3, main = "Sample Graph",
        xlab = "X Values", ylab = "Y Values", 
        names = c("First","Second","Third"))

Simple Boxplot with labels in R

Notice the difference in both the graphs with the addition of labels in the second graph.

We can also add the notch parameter and set it to TRUE to add a notch to the boxes and help in studying the medians of data. To make the boxes on the other axis, we can set the horizontal parameter to be TRUE.

boxplot(v1,v2,v3, main = "Sample Graph",
        xlab = "X Values", ylab = "Y Values", 
        names = c("First","Second","Third"), notch = TRUE, horizontal = TRUE)

Simple Boxplot with notch parameter in R