Homework 8

Key

Click link above for answers to homework 8.

Instructions

Answer each of the following questions. Be sure to display all your code in the rendered version (use echo: true throughout1).

Exercises

Question 1:

Given a vector of birthdates2, write a function to compute the age in years3.

Question 2:

For each of the following functions list all arguments that use tidy evaluation and describe whether they use data-masking or tidy-selection: distinct(), count(), group_by()4, rename_with(), slice_min(), slice_sample().

Question 3:

Build up a rich plotting function by incrementally implementing each of the steps below:

  • Draw a scatterplot given dataset and x and y variables.
  • Add a line of best fit (i.e. a linear model with no standard errors)5.
  • Add a title that includes the names of the variables used.

Test your function with the built-in cars, swiss, and iris datasets.

Due Dates

# Homework Due Peer Review Due
1 2 April 7 April
2 9 April 14 April
3 16 April 21 April
4 23 April 28 April
5 30 April 5 May
6 7 May 12 May
7 14 May 19 May
8 21 May 26 May
9 28 May 2 June

Footnotes

  1. You can make this a global option for your whole document by putting it directly in the YAML of your qmd:

    ---
title: "My Document"
execute:
  echo: true
---
    ↩︎

  2. Assume mdy format for this vector.↩︎

  3. Depending upon how you want to solve this problem, the lubridate functions today() and time_length() could be useful here :)↩︎

  4. Note: group_by() doesn’t list what type of tidy evaluation it uses for its ... argument but you can find the answer in the introduction to this article.↩︎

  5. geom_smooth() has a method and se argument that will be necessary to specify here.↩︎