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Exercise

Accessing data

Since the focus of this course is statistical modeling, we'll assume you already know how to get data into R. Many of the datasets will come from a package written specifically for this course: statisticalModeling. This package is already installed on the DataCamp servers. To use it on your own computer, you'll have to install it there.

To access data contained in an R package, you have a few options:

  1. Use the data() function: data("CPS85", package = "mosaicData")
  2. Refer to the package using double-colon notation: mosaicData::CPS85
  3. Load the package, then refer to the dataset by name: library(mosaicData); CPS85

Let's get some quick practice with these three approaches before moving on.

Instructions
100 XP
  • Use the data() function to load the Trucking_jobs data frame from statisticalModeling. Both the name of the dataset and the package it's coming from should be surrounded with double quotes (see example above).
  • Use nrow() to find the number of rows in Trucking_jobs.
  • Use names() to find the names of variables in the mosaicData::Riders data (using double-colon notation).
  • Load the ggplot2 package.
  • Look at the head() of the the diamonds dataset, which is contained in ggplot2. You can refer to the dataset directly by name, since the package is loaded.