Agenda

In this module, we will learn to

  • modify the appearance of all non data components of the plot such as
    • axis
    • legend
    • panel
    • plot area
    • background
    • margin
    • facets
  • use different themes

Libraries

library(ggplot2)
library(dplyr)
library(tidyr)

Scatter Plot

p <- ggplot(mtcars) +
  geom_point(aes(disp, mpg))
p

Axis Title

p + theme(axis.title.x = element_text(color = "red", size = 10))

Axis Text

p + theme(axis.text.x = element_text(color = "red", size = 10))

Axis Font

p + theme(axis.text = element_text(color = "red", size = 10, face = "italic"))

Axis Ticks

p + theme(axis.ticks = element_line(color = 'blue', size = 1.25, linetype = 2), 
          axis.ticks.length = unit(1, "cm"))

Axis Line

p + theme(axis.line = element_line(color = 'red', size = 1.5, linetype = 3))

Legend

p <- ggplot(mtcars) +
  geom_point(aes(disp, mpg, color = factor(cyl), shape = factor(gear)))
p

Background

p + theme(legend.background = element_rect(fill = 'gray', linetype = 3,  
          color = "black"))

Margin

p + theme(legend.margin = margin(4, 8, 4, 8))

Spacing

p + theme(legend.spacing = unit(1.5, "cm"))

Key

p + theme(legend.key = element_rect(fill = 'red'),
          legend.key.size = unit(0.4, "cm"))

Text

p + theme(legend.text = element_text(color = 'green', face = 'italic'))

Title

p + theme(legend.title = element_text(color = 'blue', face = 'bold'),
          legend.title.align = 0.1)

Position

p + theme(legend.position = "top")

Direction

p + theme(legend.direction = "horizontal")

Box

p + theme(legend.box = "horizontal",
  legend.box.background = element_rect(fill = "gray"),
  legend.box.spacing = unit(1, "cm"), legend.box.just = "left",
  legend.box.margin = margin(4, 8, 4, 8))

Panel

p <- ggplot(mtcars) +
  geom_point(aes(disp, mpg))
p

Panel Background

p + theme(panel.background = element_rect(fill = 'gray'))

Panel Border

p + theme(panel.border = element_rect(fill = NA, color = 'blue', 
          linetype = 1, size = 2))

Panel Grid

p + theme(panel.grid = element_line(color = 'blue', linetype = 2, size = 0.5))

Panel Grid (Major)

p + theme(panel.grid.major.x = element_line(color = 'blue', 
          linetype = 2, size = 0.5))

Panel Grid (Minor)

p + theme(panel.grid.minor.y = element_line(color = 'red', 
          linetype = 3, size = 0.2))

Plot Area

p <- ggplot(mtcars) +
  geom_point(aes(disp, mpg)) + 
  ggtitle('Theme Modification')
p

Plot Background

p + theme(plot.background = element_rect(color = 'blue', 
          fill = '#4682B4'))

Plot Title

p + theme(plot.title = element_text(color = 'red'))

Plot Margin

p + theme(plot.margin = unit(c(1, 1, 1, 1), "cm"))

Facets

p <- ggplot(mtcars) +
  geom_point(aes(disp, mpg)) + 
  facet_grid(~cyl)
p

Strip Background

p + theme(strip.background = element_rect(color = 'red', 
          fill = '#4682B4'))

Strip Text

p + theme(strip.text = element_text(face = 'italic', size = 8,
          color = 'red'))

Themes

Classic Dark on Light

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_bw()

Default Gray

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_gray()

Light

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_light()

Minimal

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_minimal()

Dark

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_dark()

Classic

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_classic()

Void (Empty)

ggplot(mtcars) +
  geom_point(aes(disp, mpg)) +
  theme_void()

To do: - add intro slide - section for axis, legend, panel, plot area, facets and themes