Assignment 1

Publish to GitHub by Thursday April 7th, 11:55pm.

It's dangerous to go alone! Take these Git Notes.

Start early so that you can get help on Piazza and in office hours. Now is the time to work out any problems you have with submitting assignments via git.

Part A: About You 😃

If you're reading this on GitHub, clone this repository to get started. Cloning is explained in the Git Notes.

For this part of the assignment, you'll create a short description of yourself and publish it to the web. The goal is to get comfortable with text editors, git, and the command line.

1. Get a text editor. Since we'll be using R a lot in this class, the best choice is RStudio. Some other options are Atom, Notepad++ (Windows), and TextWrangler (Mac OS X). If you want a challenge, Emacs and Neovim are more advanced, but much less beginner-friendly. Microsoft Word and other office suites are designed to edit formatted text files, not plain text files, so they are not a good substitute for a text editor.

2. Open your text editor. Create a new text document and write a 5-6 sentence description of yourself, which should include:

   • Your first and last name
   • Your year and major
   • What you want to learn in STS 98
   • A little about you (this can be anything you want to tell)

   While writing, keep in mind that you'll be publishing this information publicly online. Save the file in your assignment repository as description.txt.

   (optional) Format the file with Markdown, and save it as description.md instead.

3. Copy a clear photo of your face. Keep it appropriate and under 1 MB. Name the file photo, but keep the original extension. For example: if the original file is IMG2351.jpg, name the copy photo.jpg.

Now you need to publish your work.

1. Open the command line and change the working directory to your assignment repository.

2. Use the git add command to stage your description and photo. Remember, you can check which files you've added with the git status command. You can unstage a file with the git reset HEAD command.

3. Once your files are staged, use git commit -m to create a commit. Write a one-sentence commit message that describes your work. Make sure to surround the commit message in quotes. For example,

   git commit -m "Wrote a totally awesome bio!"
   

4. Push your commits to GitHub with the git push command. Git will ask you for your GitHub username and password. You'll need an internet connection for this step.

5. Open GitHub in your web browser and double-check that your files are now online.

Part B: Data Detective 🔍

For this part of the assignment, you'll investigate an unfamiliar R function and a mystery data set. The goal is to take your first few steps as an R user.

Helpful R commands: ?, ??, dim, nrow, ncol, length, names, rownames, colnames, head, tail, typeof, class, readRDS

1. R includes a function called which.max.

   1. How many parameters does the function have? Describe each of them.
   2. What does it do?
   3. Give an example of what it does with the vector c(3, -1, 4, 2.5).
   4. What happens if there's a tie? How did you figure this out?

2. Load the data set mystery.rds.

   1. What's the type of this data? What's the class?
   2. How big is the data?
   3. Briefly describe five of the columns.
   4. What do you think this data represents? Explain your reasoning.
   5. Searching the web is a good way to get more information (but always be skeptical). Search the web to verify your guess about what the data represents. Were you correct? Did you find any new information?
   6. There are many variables this data set doesn't include. For example, it doesn't include each person's hair color. Suggest two variables that aren't included. For each variable, write a paragraph that gives a description and a discussion of why you think the variable is meaningful. It might help to imagine you're someone from 1912. What would you want to know?
   7. Do you think this data set is accurate? In a paragraph, discuss how and why there might be inaccuracies or errors.

Save your answers to a PDF file named partB.pdf and your code to a text file named partB.R, both in your assignment repository. Add, commit, and push the files to GitHub following the same steps you used to publish Part A. Please do not commit any .docx or .odt files.

Microsoft Word, Libre Office, RStudio, and others can export to PDF.