Mixing Charts


This post shows how to use the gridExtra library to combine several ggplot2 charts on the same figure. Several examples are provided, illustrating several ways to split the graphing window.

Mixing multiple graphs on the same page is a common practice. It allows to summarize a lot of information on the same figure, and is for instance widely used for scientific publication.

The gridExtra package makes it a breeze. It offers the grid.arrange() function that does exactly that. Its nrow argument allows to specify how to arrange the layout. For more complex layout, the arrangeGrob() functions allows to do some nesting.

Here are 4 examples to illustrate how gridExtra works:

# Libraries
library(ggplot2)
library(gridExtra)
 
# 4 simple graphics
g1 <- ggplot(mtcars, aes(x=qsec)) + geom_density(fill="slateblue") + theme_bw()
g2 <- ggplot(mtcars, aes(x=drat, y=qsec, color=cyl)) + geom_point(size=5) + theme(legend.position="none") + theme_bw()
g3 <- ggplot(mtcars, aes(x=factor(cyl), y=qsec, fill=cyl)) + geom_boxplot() + theme(legend.position="none") + theme_bw()
g4 <- ggplot(mtcars , aes(x=factor(cyl), fill=factor(cyl))) +  geom_bar() + theme_bw()
 
# Plots
grid.arrange(g2, arrangeGrob(g3, g4, ncol=2), nrow = 2)
grid.arrange(g1, g2, g3, nrow = 3)
grid.arrange(g2, arrangeGrob(g3, g4, ncol=2), nrow = 1)
grid.arrange(g2, arrangeGrob(g3, g4, nrow=2), nrow = 1)

The function ggarrange() from the package ggpubr also allow to mix multiple graphs:

# Libraries
library(ggpubr)
 
# Plots
ggarrange(g1, g2, g3, g4, ncol = 2, nrow = 2, heights = c(0.7, 0.3), align = "v")




Contact

This document is a work of the statistics team in the Biostatistics and Medical Information Department at Saint-Louis Hospital in Paris (SBIM).
Developed and updated by Noémie Bigot and Anouk Walter-Petrich
noemie.bigot@aphp.fr; anouk.walter-petrich@u-paris.fr

Based on The R Graph Gallery by Yan Holtz.

SBIM