Chapter 4 Histogram

You should use this method if the data is:

• Numeric

4.1 One variable

4.1.1 Basic Histogram

Basic plot:

wage_df %>% 
  ggplot(aes(x = wage)) +
  geom_histogram()

4.1.2 Bins

Adjust number of bins:

wage_df %>% 
  ggplot(aes(x = wage)) +
  geom_histogram(bins = 20)

4.1.3 Binwidth

Instead of using bins, you can also change the binwidth:

wage_df %>% 
  ggplot(aes(x = wage)) +
  geom_histogram(binwidth = 10)

4.2 Two variables

4.2.1 Faceted histogram

wage_df %>% 
  ggplot(aes(x = wage)) +
  geom_histogram() +
  facet_wrap( ~ education)

4.2.2 Stacked histogram

wage_df %>% 
  ggplot(aes(x = wage, fill = education)) +
  geom_histogram(alpha = 0.4)