Grammar of graphics II

Author

Jeffrey R. Stevens

Published

April 3, 2023

  1. Using the mtcars data, create a scatterplot of the fuel efficiency as a function of weight.
library(tidyverse)
── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
✔ dplyr     1.1.4     ✔ readr     2.1.5
✔ forcats   1.0.0     ✔ stringr   1.5.1
✔ ggplot2   3.5.0     ✔ tibble    3.2.1
✔ lubridate 1.9.3     ✔ tidyr     1.3.1
✔ purrr     1.0.2     
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
mtcars |> 
  ggplot(aes(x = wt, y = mpg)) +
  geom_point()

  1. Repeat the scatterplot, but make the points violet open squares of size 5.
mtcars |> 
  ggplot(aes(x = wt, y = mpg)) +
  geom_point(color = "violet", shape = 0, size = 5)

  1. Repeat the scatterplot but with separate colors for cylinder levels.
mtcars |> 
  ggplot(aes(x = wt, y = mpg, color = cyl)) +
  geom_point()

  1. Why does the legend look like that? Fix it so there are separate colors for cylinder levels.
mtcars |> 
  ggplot(aes(x = wt, y = mpg, color = as.factor(cyl))) +
  geom_point()

  1. Overlay separate regression lines for each cylinder level.
mtcars |> 
  ggplot(aes(x = wt, y = mpg, color = as.factor(cyl))) +
  geom_point() +
  geom_smooth(method = "lm")
`geom_smooth()` using formula = 'y ~ x'

  1. Overlay a single firebrick regression line over the points with a firebrick1-colored confidence band.
mtcars |> 
  ggplot(aes(x = wt, y = mpg)) +
  geom_point(aes(color = as.factor(cyl))) +
  geom_smooth(method = "lm", color = "firebrick", fill = "firebrick1")
`geom_smooth()` using formula = 'y ~ x'

  1. Plot the mean and standard error of the mean of fuel efficiency for each level of cylinder and color them sienna.
mtcars |> 
  ggplot(aes(x = as.factor(cyl), y = mpg)) +
  stat_summary(color = "sienna")
No summary function supplied, defaulting to `mean_se()`