Basic Statistics for Variables in Datasets

• Most data in R come in the form of a data frame, which we will refer to as a dataset.

• It is simply a rectangular arrangement of data, where each row corresponds to an individual or case that we study, and each column corresponds to a specific question about the cases.

• In statistics, we typically call these columns variables.

• Most of the basic functions provide a formula interface. You will need the hanoverbase package in order to use this interface.

• Some examples:

  data(counties)
  View(counties)
  favstats(~pop2010, data=counties)   # Five number summary
  mean(~pop2010, data=counties)     # Average population for counties
  median(~pop2010, data=counties)   # Median population for counties
  median(~pop2010|state, data=counties)  # Median county population by state