Violin Plot with the vioplot package



Violin plots are useful to compare the distribution of several groups. I strongly advise to use ggplot2 to build them, but the vioplot library is an alternative in case you don’t want to use the tidyverse.

Violin Section Violin theory

The Vioplot library builds the violin plot as a boxplot with a rotated kernel density plot on each side. If you want to represent several groups, the trick is to use the with function as demonstrated below.

Note: consider using the ggplot2 package as shown in graph #95.

# Load the vioplot library
library(vioplot)
 
# Create data
treatment <- c(rep("A", 40) , rep("B", 40) , rep("C", 40) )
value <- c( sample(2:5, 40 , replace=T) , sample(c(1:5,12:17), 40 , replace=T), sample(1:7, 40 , replace=T) )
data <- data.frame(treatment,value)
 
# Draw the plot
with(data , vioplot( 
  value[treatment=="A"] , value[treatment=="B"], value[treatment=="C"],  
  col=rgb(0.1,0.4,0.7,0.7) , names=c("A","B","C") 
))

Related chart types


Violin
Density
Histogram
Boxplot
Ridgeline



Contact

This document is a work by Yan Holtz. Any feedback is highly encouraged. You can fill an issue on Github, drop me a message on Twitter, or send an email pasting yan.holtz.data with gmail.com.

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