Problem Set 0

Problem Set 0: Getting Set Up!

The rest of the semester will see you working on data science questions using R. As such, your first problem set will have you:

1. Install R on your computer.
2. Install RStudio on your computer.
3. Create a directory (i.e., a folder with a set of subfolders) for this class.
4. Create a new .Rmd file and Save as....
5. Modify the .Rmd file and knit it.

1. Installing R

R is going to be the only programming language we will use. R is an extensible statistical programming environment that can handle all of the main tasks that we’ll need to cover this semester: getting data, analyzing data and communicating data analysis.

Download R here: https://cran.r-project.org/. Make sure to choose the version that works with your operating system!

2. Installing RStudio

When we work with R, we communicate via the command line. To help automate this process, we can write scripts, which contain all of the commands to be executed. These scripts generate various kinds of output, like numbers on the screen, graphics or reports in common formats (pdf, word). Most programming languages have several I ntegrated D evelopment E nvironments (IDEs) that encompass all of these elements (scripts, command line interface, output). The primary IDE for R is RStudio.

Download RStudio here: https://rstudio.com/products/rstudio/download/. You need the free RStudio desktop version.

3. Setting up Directories

In each class, we’re going to include some code and text in one file, and data in another file. You’ll need to download both of these files to your computer. You need to have a particular place to put these files. Computers are organized using named directories (sometimes called folders). Don’t just put the files in your Downloads directory. One common solution is to created a folder on your computer named after the class: PSC4175.

You could just throw everything related to the class into this folder. However, this will quickly get messy. I recommend you create a “sub-folder” (or “sub-directory”) within PSC4175 called Lecture_1. (You might also want to create similar sub-folders for Lecture_2.) Inside Lecture_1, create two additional sub-folders: code and data. When you’re done, your class directory should look like this:

• PSC4175
  • Lecture_1
    • code
    • data

4. Create an .Rmd file

Open RStudio, then create a new .Rmd file. To do this, click on File → New File → R Markdown....

Settings for .Rmd file

You will then be asked to determine a bunch of settings for this .Rmd document. For example, you can choose whether you want to create a “Document”, “Presentation”, “Shiny”, or “From Template” on the left. You can set the “Title:” “Author:” and “Date:” on the top-right. And you can choose the “Default Output Format:” to be either “HTML”, “PDF”, or “Word”. You should not change any of these settings. Their defaults (“Document”, “Untitled”, “[Your name]”, “[Today’s Date]”, and “HTML”) are sufficient. Just click “OK”.

Saving .Rmd file

This will open a new .Rmd file! Now you should change the title of the file to “Problem Set 0” and the author to your name. You should then save the file in your code folder with the file name [Last Name]_PS0.Rmd by clicking File → Save As....

5. Modify and knit

Now, delete all of the default text in your .Rmd file from line 12 down to the bottom. Then write the following on line 12:

# Problem Set 0
I can take notes by just typing normally.

Now let’s knit the file by clicking the down arrow next to the Knit button on the top of the window and selecting Knit to PDF. If this didn’t work, see Homework 1 for instructions.

```{r}
2+2
```