AE 03: Tidying Stat Sci majors

Application exercise
Important

These are suggested answers. This document should be used as reference only, it’s not designed to be an exhaustive key.

Data

The data come from the Office of the University Registrar.

library(tidyverse)

majors <- read_csv("data/majors.csv")

statsci_majors <- majors |>
  filter(
    department == "Statistical Science",
    academic_plan != "Minor"
  )

And let’s take a look at the data.

statsci_majors
# A tibble: 4 × 17
  department      academic_plan `2026` `2025` `2024` `2023` `2022` `2021` `2020`
  <chr>           <chr>          <dbl>  <dbl>  <dbl>  <dbl>  <dbl>  <dbl>  <dbl>
1 Statistical Sc… BS                49     45     39     54     32     35     27
2 Statistical Sc… BS2               28     23     20     27     16     17     17
3 Statistical Sc… BA                 2     NA      1      2     NA     NA      1
4 Statistical Sc… BA2                1     NA     NA     NA     NA      2      1
# ℹ 8 more variables: `2019` <dbl>, `2018` <dbl>, `2017` <dbl>, `2016` <dbl>,
#   `2015` <dbl>, `2014` <dbl>, `2013` <dbl>, `2012` <dbl>

Pivoting

  • Demo: Pivot the statsci data frame longer such that:

    • Each row represents a degree type / year combination
    • year and number of graduates for that year are columns in the data frame
    • The resulting year column is numeric
# add code here
  • Your Turn: Now, repeat your code from above, but this time save the result to a new variable name.
# add code here

Plotting

  • Your turn: Now we will start making our plot, but let’s not get too fancy right away. Just get the geoms right for now and use default colors for different academic plans.
# add code here
  • Question: Why was the pivot necessary in order to create this plot?

Add your response here!

  • Question: What aspects of the plot need to be updated still?

Add your response here.

  • Demo: Update statsci_majors_longer to fix the discontinuities.
# add code here
  • Demo: Update x-axis scale such that the years displayed go from 2012 to 2026 in increments of 2 years. Do this by adding on to your pipeline from earlier.
# add code here
  • Demo: Update line colors using the following level / color assignments. Once again, do this by adding on to your pipeline from earlier.

    • “BS” = “cadetblue4”

    • “BS2” = “cadetblue3”

    • “BA” = “lightgoldenrod4”

    • “BA2” = “lightgoldenrod3”

# add code here
  • Your turn: Update the plot labels (title, subtitle, x, y, and caption) and use theme_minimal(). Once again, do this by adding on to your pipeline from earlier.
# add code here
  • Demo: Move the legend into the plot, make its background white, and its border gray.
# add code here
  • Demo: Finally, set fig-width: 8 and fig-height: 5 for your plot in the chunk options.
# add code here