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Solutions to ggplot2: Elegant Graphics for Data Analysis

3 Individual geoms

3.1 Exercises

1. What geoms would you use to draw each of the following named plots?

  • Scatterplot: geom_point()
  • Line chart: geom_line()
  • Histogram: geom_histogram()
  • Bar chart: geom_bar()
  • Pie chart: ggplot2 does not have a geom to draw pie charts. One workaround, according to the R Graph Gallery is to build a stacked bar chart with one bar only using the geom_bar() function and then make it circular with coord_polar()


2. What’s the difference between geom_path() and geom_polygon()?

  • geom_polygon draws the same graph (lines) as geom_path, but it fills these lines with color. See below:


3. What’s the difference between geom_path() and geom_line()

geom_line() connects points from left to right, whereas geom_path() connects points in the order they appear in the data. See below:


4. What low-level geoms are used to draw geom_smooth()? What about geom_boxplot() and geom_violin()?

(kangnade)

  • geom_point(), geom_path(), and geom_area() are used to draw geom_smooth().
  • geom_rect(), geom_line(), geom_point() are used for geom_boxplot().
  • geom_area() and geom_path() are used for geom_violin()