• You're going to need to do this for your final project (details coming soon)
• It's not rocket science/brain surgery, but it still takes practice.

• Excel .xlsx files aren't the best file format as they not only contain the data, but also lots of Microsoft metadata (data about the data) that we don't need.
• Alternative: Comma-separated values .csv files are a minimalist format for spreadsheet data.

• A .csv file (example) is just data and no fluff:
  • Rows are separated by line breaks.
  • Values for a given row (i.e. variables) are separated by commas. Each row has equal number of commas.
  • The first row is typically a header row with the column/variable names

Note .csv files are in tidy data format.

You can convert .xlsx files to .csv format from Excel (and Google Docs):

• Go to File -> Save As… -> File Format -> Windows Comma Separated (.csv)
• Add .csv to the filename
• Click "Save As"

Today you will load the DD_vs_SB.csv file that contains the Dunkin Donuts and Starbucks data from Question 2 from Midterm II so that you can use it for Problem Set 07.

1. From the Problem Sets page, upload both PS-07.Rmd and DD_vs_SB.csv to your Problem Set folder on RStudio server.
2. In the RStudio Environment Panel -> "Import Dataset" -> From Local File… -> Select DD_vs_SB.csv -> Open
3. Make sure "Heading" is set to "Yes". This tells RStudio that the first row are the variable names.
4. Click Import
5. The View() panel should pop up with the data. Make sure the variable names are correct.

Now look at your console. You should see a line that looks something like:

DD_vs_SB <- read.csv("~/Problem_Sets/DD_vs_SB.csv")

This is the line of code that loads the CSV file into R and assigns it to an object called DD_vs_SB, which you will be working with.

1. Copy your version of the above line of code into the code block for Question 2 of PS-07.Rmd
2. Knit the file to test that it works
3. If so, start PS-07.Rmd!