• Faceting creates multiple plots based on the data’s subsets, allowing for easy comparisons.

• ggplot2 offers two main functions for faceting: facet_wrap() and facet_grid().

• Compare different subsets of your dataset within the same visual context.

• Identify patterns, trends, and outliers across groups more easily.

• facet_wrap() arranges plots in a specified number of rows or columns, wrapping around to create a compact layout.

library(ggplot2)
ggplot(mpg, aes(x = displ, y = hwy)) + 
  geom_point(aes(color = class)) + 
  facet_wrap(~ class)

• You can customize the layout with nrow or ncol and control the scales with scales argument.

ggplot(mpg, aes(x = displ, y = hwy)) + 
  geom_point(aes(color = class)) + 
  facet_wrap(~ class, nrow = 2, scales = "free_y")

• facet_grid() arranges plots in a grid based on the values of one or two variables.

ggplot(mpg, aes(x = displ, y = hwy)) + 
  geom_point(aes(color = class)) + 
  facet_grid(rows = vars(drv), cols = vars(cyl))

• Use the scales argument to control whether scales are shared across the grid and space to control the spacing of panels.

ggplot(mpg, aes(x = displ, y = hwy)) + 
  geom_point(aes(color = class)) + 
  facet_grid(rows = vars(drv), cols = vars(cyl), scales = "free", space = "free")

Use facet_wrap() to create individual scatter plots for each class of vehicle, showing the relationship between displ (engine displacement) and hwy (highway miles per gallon).

ggplot(mpg, aes(x = displ, y = hwy)) +
  geom_point() +
  facet_wrap(~ class)

Modify the previous answer such that the scatter plots are organised into 3 rows with each plot using its own y-axis scale.

ggplot(mpg, aes(x = displ, y = hwy)) +
  geom_point() +
  facet_wrap(~ class, nrow = 3, scales = "free_y")

Construct a ggplot2 command using facet_grid() to create a grid of plots by drv and cyl.

ggplot(mpg, aes(x = displ, y = hwy)) +
  geom_point() +
  facet_grid(drv ~ cyl)

Modify the previous to allow each plot to have its own y-axis.

ggplot(mpg, aes(x = displ, y = hwy)) +
  geom_point() +
  facet_grid(drv ~ cyl, scales = "free_y")