General Knowledge about ggplot2

ggplot2 is a R package dedicated to data visualization. It can greatly improve the quality and aesthetics of your graphics. It allows to build and custom almost any type of chart.

geom_ functions

ggplot2 builds charts through layers using geom_ functions:

geom_annotate geom_error geom_hline geom_label geom_point geom_ribbon geom_smooth geom_text geom_vline

A set of pre-built themes

It is possible to customize any part of a ggplot2 chart thanks to the theme() function. Here is a glimpse of the available themes. You can click on one of the themes to get a brief overview.

→ ggplot2

default theme_bw() theme_minimal() theme_classic() theme_gray()

→ ggthemes

theme_excel() theme_economist() theme_fivethirtyeight() theme_tufte() theme_gdocs() theme_wsj() theme_calc() theme_hc()

→ other

theme_article() theme_pubclean() theme_bigstatsr() theme_ipsum()

ggplot2 theme

plotly turns your plot interactive

Another awesome feature of ggplot2 is its link with the plotly library. It allows to make interactive charts.

# Libraries
library(ggplot2)
library(plotly)
library(gapminder)

# Interactive plot
p <- gapminder %>%
  filter(year==1977) %>%
  ggplot( aes(gdpPercap, lifeExp, size = pop, color=continent)) +
  geom_point() +
  theme_bw()
ggplotly(p)



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