In jasonmtroos/rook: Introduction to Data Visualization, Web Scraping, and Text Analysis in R

knitr::opts_chunk$set(echo = TRUE)
library(rook)

Welcome to the r rook::course_title() course offered by r toupper(rook::program()). Because we have more material to cover than we have time together, you will need to do a few things before our first meeting.

WARNING: Do not skim this document. Read it in full.

Familiarity with R

You must have prior experience writing code in the R programming language.You do not need to be an expert in R. But this course is not an introduction to programming. I will assume you understand the basics of R, such as expressions, functions, conditional statements, loops, etc.

If you are not particularly comfortable writing code in R, or perhaps just generally unsure about your level of preparedness, it is important that you practice writing code in R so that you can get the most out of the course. I created a series of R tutorials for my MSc course "Marketing Analytics." Please download the tutorials, unzip them, and follow along (reading and coding as you go). You do not need to be familiar with all of the material in these tutorials---in fact, we will cover much of this material as part of the class---but at the same time, the material in these tutorials shouldn't be entirely alien to you. A good test is whether you already know everything in Assignment 1, plus how to write basic statements using the if, for, and function statements in R (which are not covered in Assignment 1, but are important for our course). If you know all of that, and can comprehend the material in the later assignments (even if it is unfamiliar), then you are probably in fine shape for the course.

Software

Prior to the first session, you must have the following programs installed on whichever laptop you will bring to the course sessions:

• git
• R
• RTools (Windows only)
  • Be sure that you install this to your local hard drive, and not to a network share
• RStudio

Instructions for each of these follow.

Git

Git is a program for keeping track of changes you make to your code over time.

Install git on your computer if you do not already have it. You can download git from https://git-scm.com/downloads and find detailed installation instructions at https://git-scm.com/book/en/v2/Getting-Started-Installing-Git.

R and RStudio

RStudio provides an integrated development environment (IDE) for writing and executing scripts written in R.

Install R on your computer if you do not already have it installed. You can download R from https://cloud.r-project.org/. If you are working on a Windows computer, you should also install RTools.

If you have an older version of R on your computer, now might be a good time to upgrade to the latest version. As of the time of writing, the current version of R is r rversions::r_release()$version. To see the version on your computer, execute the following code in the R Console (or R Studio if already installed):

version$version.string

Note: Because R has just released a major version, you might want to keep using an older version. I have decided to upgrade to 4.0. But there may be problems for those of us who upgrade, and problems for those of us who do not. Sorry, bad timing...

Install RStudio on your computer if you do not already have it. You can download RStudio from https://www.rstudio.com/products/rstudio/download/. Note that RStudio offers both commercial and free versions; you should install the free version.

Note: Jason is running r paste(unlist(R.version[c('version.string', 'nickname')]), collapse = " ") and RStudio r rstudioapi::getVersion() at the time of writing.

R Packages

Open an R console and execute the following:

install.packages('devtools', dependencies = TRUE)
install.packages('pkgbuild', dependencies = TRUE)
install.packages('tidyverse', dependencies = TRUE)
install.packages('Hmisc', dependencies = TRUE)
install.packages('tm', dependencies = NA)   # <-- this one is NA instead of TRUE
install.packages('rtweet', dependencies = TRUE)
install.packages('lda', dependencies = TRUE)

Windows users will want to execute the following R code after they have installed the devtools package and installed RTools. Open RStudio and type the following into the R Console, then hit Enter.

pkgbuild::setup_rtools()

OS X users may need to install the XCode command-line tool chain, by opening a Terminal window and executing the following command:

xcode-select --install

GitHub account

We will use GitHub to share code and data. Please sign up for an account at https://github.com/ if you do not already have one.

After you have created a GitHub account, you need to do a little bit of configuration:

• Start a new terminal (OS X) or bash (Linux) or git-bash (Windows) session
• Execute the following commands, substituting your information
• Note: Use the email address associated with your GitHub account

git config --global user.name "Your Name"
git config --global user.email "[e-mail]"

• OS X users might need to issue the following commands as well

git credential-osxkeychain
git config --global credential.helper osxkeychain

Twitter accounts

In order to access the Twitter API (Session 3), you need to have the appropriate accounts and security credentials:

• Create a Twitter account if you do not have one already
• Visit https://developer.twitter.com/ and apply for a Developer Account. It takes a few days for the account to be approved, so do this as soon as possible. Do not delay. Do not wait until just before Session 3. Do it now.
• Follow this tutorial which provides detailed instructions for setting up programmatic access to Twitter using the rtweet package. I recommend using Authorization Method #2 (Access token/secret method).

Even more things you can do!

The following needs to be done prior to Session 3. Given the short time frame for this course, it is advised that you complete as much of this now as you can (be sure to review the technical material just prior to Session 3, though).

HTML

• Review or learn the basics of HTML
• Play this game to learn CSS
• Install SelectorGadget for Chrome and try it, or else do a lot of playing around with "Inspect Element" in your favorite browser
• Skim this Wikipedia article about CGI query strings so that you have a sense of why I might infer that if this page generates page 1 of data: http://some-site.com/show_data?page=1, then this page: http://some-site.com/show_data?page=2 will probably generate page 2.

The tm package

• Read and follow (type along with) this tutorial:

vignette('tm', package = 'tm')

(or https://cran.r-project.org/web/packages/tm/vignettes/tm.pdf if that doesn't work...)

Concepts behind sentiment analysis

• Skim pp 1--7 of Gonçalves, et al. "A Benchmark Comparison of State-of-the-Practice Sentiment Analysis Methods." arXiv preprint arXiv:1512.01818 (2015). http://arxiv.org/pdf/1512.01818.pdf

jasonmtroos/rook documentation built on May 24, 2020, 3:16 p.m.