The R ggplot2 boxplot is useful for graphically visualizing the numeric data group by specific data. Let us see how to Create an R ggplot2 boxplot, Format the colors, changing labels, drawing horizontal boxplots, and plot multiple boxplots using R ggplot2 with an example.
For this r ggplot2 Boxplot demo, we use two data sets provided by the R Programming, and they are: ChickWeight and diamonds data set
Create R ggplot2 Boxplot
In this example, we show how to create a Boxplot using the ggplot2 package in R. For this ggplot2 boxplot demo, we are going to use the ChickWeight data set, provided by the Studio.
# Create a R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(ChickWeight, aes(x = Diet, y = weight)) + geom_boxplot()
Change Colors of a ggplot2 Boxplot in R
In this example, we show how to change the R ggplot Boxplot box colors using fill argument
- fill: Please specify the color you want to use for your Boxplot. Type colors() in your console to get the list of colors available in R programming.
TIP: ggplot2 package not installed by in R Programming default. Please refer Install R Packages article to understand installing the package.
# Add Color to R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(diamonds, aes(x = cut, y = price)) + geom_boxplot(fill = "midnightblue")
Change Colors of a ggplot2 Boxplot in R example 2
In this example, we change the R ggplot Boxplot box colors using column data. Here, we are using the cut column data to differentiate the colors
NOTE: If you require to import data from external files, then please refer to R Read CSV to understand the steps involved in CSV file import
# Add Color to R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(diamonds, aes(x = cut, y = price, fill = cut)) + geom_boxplot(outlier.colour="black", outlier.shape=16, outlier.size=2)
Change Outliners of R ggplot2 Boxplot
In this example, we show how to change the R ggplot boxplot outliners colors using the following arguments
- outlier.color: Please specify the color you want to use for your outliner. Type colors() in your console to get the list of colors available in R programming
- outlier.shape: Please specify the shape you want to use for the outliner for the R ggplot boxplot.
- outlier.size: Specify the size of the outliner.
# Change Outliers in a R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(diamonds, aes(x = cut, y = price, fill = cut)) + geom_boxplot(outlier.color = "seagreen", outlier.shape = 8, outlier.size = 2)
Add Mean to R ggplot2 Boxplot
In this example, we add Mean value to R ggplot boxplot using the stat_summary argument
# Adding Mean to a R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(diamonds, aes(x = cut, y = price, fill = cut)) + geom_boxplot() + stat_summary(fun.y = "mean", geom = "point", shape = 8, size = 2, color = "white")
Alter Legend position of an R ggplot2 Boxplot
By default, ggplot position the legend at the right side of a Boxplot in R. In this example, we change the legend position from right to the top. Note, You can use legend.position = “none” to completely remove the legend.
# Alter lengend Position in a a R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(diamonds, aes(x = cut, y = price, fill = cut)) + geom_boxplot() + theme(legend.position = "top")
Notch argument in R Boxplot
Here, we draw a line on each side of the boxes using notch argument in R ggplot boxplot
- notch: It is a Boolean argument. If it is TRUE, a notch drawn on each side of the box.
TIP: If the notches of 2 plots overlapped, then we can say that the medians of them are the same. Otherwise, they are different.
# Notch argument in R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(ChickWeight, aes(x = Diet, y = weight)) + geom_boxplot(fill = "chocolate", notch = TRUE)
Horizontal ggplot Boxplot in R
In this example, we change the default vertical boxplot into a horizontal boxplot in R using coord_flip() function
# Create Horizontal R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot ggplot(ChickWeight, aes(x = Diet, y = weight)) + geom_boxplot() + coord_flip()
Multiple ggplot Boxplot in R
In this example, we show how to group multiple ggplot boxplots in R programming
# Multiple R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot Importing ggplot(diamonds, aes(x = cut, y = price, fill = clarity)) + geom_boxplot()
How to use Facets in R ggplot2 Boxplot
This R ggplot boxplot example, we draw multiple boxplots by dividing the data based on a column value. Here, we are using the clarity column data to divide the boxplots.
# Use Facet in R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot Importing ggplot(diamonds, aes(x = cut, y = price, fill = clarity)) + geom_boxplot() + facet_wrap(~ clarity)
How to use Facets in R ggplot2 Boxplot example 2
By default, facet_wrap() assign the same y-axis to all the boxplot. However, you can change it (giving independent axis) to each R ggplot boxplot by adding one more attribute called scale.
# Use Facet in R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot Importing ggplot(diamonds, aes(x = cut, y = price, fill = clarity)) + geom_boxplot() + facet_wrap(~ clarity, scale = "free")
Assigning names to R ggplot Boxplot
In this example, we assign names to ggplot2 boxplot, X-Axis, and Y-Axis using labs function
# Add Labels to R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot Importing ggplot(diamonds, aes(x = cut, y = price, fill = cut)) + geom_boxplot() + labs(title="GGPLOT BOXPLOT", x="Price in Dollars", y="Cut")
Change R ggplot2 box plot Theme
In this example, we change the default theme of an R ggplot2 box plot
- theme_dark(): We are using this function to change the ggplot2 boxplot default theme to dark. Type theme_, then R Studio intelligence shows the list of available options. For example, theme_grey().
# Change theme of an R ggplot boxplot # Importing the ggplot2 library library(ggplot2) # Create a Boxplot Importing ggplot(diamonds, aes(x = cut, y = price, fill = cut)) + geom_boxplot() + labs(title="GGPLOT BOXPLOT", x="Price in Dollars", y="Cut") + theme_dark()
