Exploratory Analysis

Data visualization, part 1. Code for Quiz 7.

  1. Load the R package we will use.
  1. Quiz questions

The quiz assumes you have watched the videos and had worked through the exercises in exercises_slides-1-49.Rmd

  1. Pick one of your plots to save as your preview plot. Use the ggsave command at the end of the chunk of the plot that you want to preview.

Modify Slide 34

ggplot(faithful) + 
   geom_point(aes(x = eruptions, y = waiting, 
                  colour = waiting > 58)) 

Modify Intro-slide 35

ggplot(faithful) + 
   geom_point(aes(x = eruptions, y = waiting),
              colour = "darkorange") 

Modify Intro-slide 36

ggplot(faithful) + 
   geom_histogram(aes(x = waiting))

Modify geom-ex-1

ggplot(faithful) + 
   geom_point(aes(x = eruptions, y = waiting), 
   shape = "square", size = 5, alpha =0.5)

Modify geom-ex-2

ggplot(faithful) + 
   geom_histogram(aes(x = eruptions, fill = eruptions > 3.2 ))

Question: Modify stat-slide-40

ggplot(mpg) + 
   geom_bar(aes(x = manufacturer))

Question: Modify stat-slide-41

mpg_counted <- mpg %>% 
  count(manufacturer, name = 'count')
ggplot(mpg_counted) + 
  geom_bar(aes(x = manufacturer, y = count), stat = 'identity')

Modify stat-slide-43

ggplot(mpg) + 
  geom_bar(aes(x = manufacturer, y = after_stat(100 * count / sum(count))))

Modify Answer to stat-ex-2

For reference see: https://ggplot2.tidyverse.org/reference/stat_summary.html?q=stat%20_%20summary#examples

Use stat_summary() to add a dot at the median of each group

ggplot(mpg) + 
  geom_jitter(aes(x = class, y = hwy), width = 0.2) +
  stat_summary(aes(x = class, y = hwy), geom = "point", 
  fun = "median", color = "blueviolet", 
  shape = "cross", size = 9)

ggsave(filename = "preview.png",
       path = here::here("_posts", "2022-03-14-exploratory-analysis"))