Exam 1 Study Guide

Weeks 1 - 6 and collaborative Git

Logistics

• You are allowed one page of notes, front and back. You wil submit this with the exam.
• You will be provided an appendix of R code and output, and a codebook with details about the data.
• I will not ask you to live code from scratch.

Take-home portion

• Released Wednesday, October 14 at 6am
• Due Thursday, October 15 at 12:30pm to github only.
• I will access the state of your repo at your last push before the deadline
• I will render your exam .qmd file and grade what comes out.
  • that means if it doesn’t render, you get a zero for this portion of the exam.

Topics to study

This exam covers weeks 1 through 6 and collaborative Git. Start with the Quiz 2 study guide, which summarizes weeks 3 - 6. Review your notes from weeks 1 and 2 too (the toolkit and ggplot2). Practice describing plots and tables in words with the writing guide.

New topics that weren’t in the quiz 2 study guide -

Collaborative Git

• Rendering, committing, and pushing are three different steps. A commit saves a snapshot on your computer. Only a push sends it to GitHub, where your teammates can see it.
• A pull brings your teammates’ work to your computer. If a push is rejected because GitHub has commits you don’t have, pull first, then push again.
• If two people edit the same line, git can’t decide which version to keep and you get a merge conflict. Edit the file to keep what you want, delete the <<<<<<<, =======, and >>>>>>> marker lines, then render, commit, and push. If you edit different parts of the file, git combines the changes on its own.
• A branch is a separate line of work, so you can make changes without touching main.
• A pull request asks for your branch to be merged into main. Opening one does not merge it. The changes reach main only when the pull request is merged, usually after a teammate reviews it.
• Key terms: clone, commit, push, pull, branch, pull request, merge, merge conflict.

Quarto rendering options

Chunk options go at the top of a chunk, one per line, starting with #|. By default, a chunk that produces an error stops the render.

Option	What it does
echo: false	Runs the code and shows the output, but hides the code.
eval: false	Shows the code but does not run it, so there is no output and no error.
include: false	Runs the code but hides both the code and the output.
warning: false	Runs the code and hides the warnings.
message: false	Runs the code and hides the messages.
error: true	Runs the code. If it produces an error, shows the error in the output and keeps rendering.

• Set an option once under execute: in the YAML header to apply it to the whole document. An option on a chunk overrides the document setting for that chunk.

Advice on how to prepare