How to create boxplots grouping into intervals x-axis values using R?

Problem

We want to create boxplots grouping into intervals the values of the x-axis, like in the example below.

Solution

Data

We generate random data and a sequence to create the intervals.

set.seed(12)
y <- rnorm(1000)
x <- rnorm(1000)
rng <- seq(-3, 3, 0.5)

Base

boxplot(y ~ cut(x, breaks = rng),las=2)

If we'd like to include not available data (NAs), we use the function addNA:

boxplot(y ~ addNA(cut(x, breaks = rng)), las = 2)

ggplot2

First we create data frame with the intervals.

library(ggplot2)
df <- data.frame(x = cut(x, breaks = rng), y = y)
ggplot(data = df, aes(x = x, y = y)) + geom_boxplot(aes(fill = x))

Related posts

Spanish version

References

• stackoverflow