ggplot2: Elegant Graphics for Data Analysis - Chapter 2

Introduction

This document contains source code and figure from chapter 2 of this fanstatic book. The book itself (and the source code) is open source. I just retyped it in order to review ggplot2. :)

Code snippet

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

ggplot(mpg, aes(cty, hwy)) + 
  geom_point()

ggplot(diamonds, aes(carat, price)) + 
  geom_point()

ggplot(economics, aes(date, unemploy)) + 
  geom_line()

ggplot(mpg, aes(cty)) + 
  geom_histogram()

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

ggplot(mpg, aes(displ, cty, colour = class)) +
  geom_point()

ggplot(mpg, aes(displ, hwy)) + 
  geom_point(aes(colour = "blue"))

ggplot(mpg, aes(displ, hwy)) + 
  geom_point(colour = "blue")

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

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth()

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth(span = 0.2)

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth(span = 1)

library(mgcv)

## Loading required package: nlme

## This is mgcv 1.8-12. For overview type 'help("mgcv-package")'.

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth(method = "gam", formula = y ~ s(x))

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth(method = "lm")

library(MASS)
ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth(method = "rlm")

ggplot(mpg, aes(drv, hwy)) + geom_jitter()

ggplot(mpg, aes(drv, hwy)) + geom_boxplot()

ggplot(mpg, aes(drv, hwy)) + geom_violin()

ggplot(mpg, aes(hwy)) + geom_histogram()

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

ggplot(mpg, aes(hwy)) + geom_freqpoly()

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

ggplot(mpg, aes(hwy)) +
  geom_freqpoly(binwidth = 2.5)

ggplot(mpg, aes(hwy)) +
  geom_freqpoly(binwidth = 1)

ggplot(mpg, aes(displ, colour = drv)) +
  geom_freqpoly(binwidth = 0.5)

ggplot(mpg, aes(displ, fill = drv)) +
  geom_histogram(binwidth = 0.5) +
  facet_wrap(~ drv, ncol = 1)

ggplot(mpg, aes(manufacturer)) +
  geom_bar()

drugs <- data.frame(drug = c("a", "b", "c"),
                    effect = c(4.2, 9.7, 6.1))
ggplot(drugs, aes(drug, effect)) + geom_bar(stat = "identity")

ggplot(economics, aes(date, unemploy / pop)) +
  geom_line()

ggplot(economics, aes(date, uempmed)) +
  geom_line()

ggplot(economics, aes(unemploy / pop, uempmed)) +
  geom_path() +
  geom_point()

year <- function(x) as.POSIXlt(x)$year + 1900
ggplot(economics, aes(unemploy / pop, uempmed)) +
  geom_path(colour = "grey50") +
  geom_point(aes(colour = year(date)))

ggplot(mpg, aes(cty, hwy)) +
  geom_point(alpha = 1 / 3)

ggplot(mpg, aes(cty, hwy)) +
geom_point(alpha = 1 / 3) +
  xlab("city driving (mpg)") +
  ylab("highway driving (mpg)")

# Remove the axis labels with NULL
ggplot(mpg, aes(cty, hwy)) +
  geom_point(alpha = 1 / 3) +
  xlab(NULL) +
  ylab(NULL)

ggplot(mpg, aes(drv, hwy)) +
  geom_jitter(width = 0.25)

ggplot(mpg, aes(drv, hwy)) +
  geom_jitter(width = 0.25) +
  xlim("f", "r") +
  ylim(20, 30)

## Warning: Removed 138 rows containing missing values (geom_point).

ggplot(mpg, aes(drv, hwy)) +
  geom_jitter(width = 0.25, na.rm = TRUE) +
  ylim(NA, 30)