cwickham / r_intro_bc_stats

This is the repo for an introduction to R using the tidyverse developed for BC Stats.

The repo currently reflects a 1 day version to be delivered Oct 2019. If you are looking for an older version, try:

• Jul 2018: A 1.5 day version
• Dec 2017: A 2.5 day version

Solutions to “Your Turns” available at r_intro_bc_stats_solutions.

License

Introduction to data science with the tidyverse by Charlotte Wickham is licensed under a Creative Commons Attribution 4.0 International License. Based on a work at https://github.com/rstudio/master-the-tidyverse.

Overview

This course will give you a feel for the complete data analysis process in R - from importing and manipulating data through visualization. You'll see how using code to capture the analysis pipeline leads to deliverables that are documented, easily reproduced and easily automated.

We'll focus on tools in the tidyverse a core set of R packages that are designed to be easy to learn, easy to use, and solve the most frequent data analysis problems.

During the course, we'll alternate between me introducing a new concept with some examples, and you applying that concept on your own. You should expect to spend at least 50% of your time writing code in RStudio on your own laptop.

The first half day is specifically for those who are new to R. Take a look at the prerequisites to see if you might be able to skip it.

Schedule

Day 1 - Getting Started with R and RStudio

On your first afternoon you'll focus on getting comfortable writing code and executing it in RStudio. We'll take things slow as you learn to navigate RStudio, learn some syntax rules, and how to get help when you get stuck. Along the way you'll meet R's most ubiquitous objects for holding data and learn to import data whether it is a CSV, SPSS or Excel data file.

By the end of the day you will be able to:

• Open a notebook in RStudio and execute the code chunks in it

• Install and load an R package

• Open the help page for a function or built-in dataset

• Identify the components of an R function: the function name and arguments

• Assign the results of a function to a new variable

• Get an overview of a dataset that is in a data frame or tibble

• Import CSV, SPSS and SAS data files

Day 2 - Visualization and Manipulation of Data

We'll start the day with visualization of data in R using the package ggplot2. You'll see how ggplot2 provides a framework for thinking about plots, which means you only need to learn one template to make almost any plot you can imagine. To practice, you'll make some of the most common kinds of data visualizations: histograms, scatterplots and time series plots, and continue building your skills as we continue through data manipulation.

In the afternoon we'll focus of the most common types of data manipulation: extracting subsets from data, adding new variables and creating grouped summaries. You'll find that doing this is quite intuitive using the dplyr package which boils down manipulation into a set of verbs like: filter(), mutate() and summarise(). Occasionally, data won't come in quite the right shape for manipulation or visualization you want to do, so we'll also talk about the key parts of the tidyr package that help to reshape not not-so-tidy data.

By the end of the day you will be able to:

• Create plots in ggplot2 to explore data

• Select variables and filter observations to subset data

• Add new variables, and transform variables

• Create grouped summaries of data

• Reshape data for use with tidy tools

Prerequisites

The first half-day is specifically for people that are new to R. You can safely join us starting on day 2 if you already:

• know how to define variables in R

• have called a few basic functions (e.g. mean()), and

• know how to open .R script files, and run code in the console

Although I'll assume on the first half-day you haven't used R, you might like to get a little experience before we meet. Some options are:

• Work through the non-interactive Chapter 1 of Hands on Programming with R, which introduces RStudio as well as basic R syntax.

• Work through the interactive chapters at Try R

• Try the free “Introduction to R” course at DataCamp

Software Requirements

You'll need to bring a laptop with R and RStudio installed. In addition, you'll want to install the following packages:

install.packages(c("tidyverse", "rmarkdown", "gapminder", "usethis"))

If you've installed the tidyverse before, re-installing it may not update all the component packages, in which case run,

tidyverse::tidyverse_update()

to identify any out-of-date packages, and follow the instructions to update them.

Don't forget to bring your power cable!

I'll also be providing some additional materials (slides, code and data) prior to our meeting, keep your eyes out for an email about soon.

Getting the materials

To download the materials, open RStudio and on the Console run:

usethis::use_course("bit.ly/rintro-bc")

After a pause, you'll be asked a few questions about the download process. The materials will be downloaded, unzipped to your Desktop, and a new RStudio session will open.

You only need to do this once. If you close RStudio, and want to pick it up again later (i.e. on the day of the training):

1. Navigate to where the folder was downloaded (this should be a folder called r_intro_bc_stats-master on your Desktop)

2. Double-click the file r_intro_bc_stats.Rproj to open up RStudio

rstudio.cloud

If you have a good internet connection, an alternative to installing the pacakges, and getting the materials, locally is to use https://rstudio.cloud/project/49127

You may need to sign up for an account (free) first.

Instructor Info

Charlotte Wickham

• [email protected]

• cwick.co.nz

• @cvwickham