FAQ

1. How do I read in a table from a web page?

In R, you can use the rvest package, which has the read_table() function.

2. How do I automate reading in tables from multiple web pages (or multiple files from disk) and combine them?

You can use a looping structure (or an *apply function in R) to iterate through a set of values (like filenames) and process each item using a function that receives the values you supply as function parameters.

3. How do I reshape and merge datasets? (What is the difference between the several types of joins and when do I use them?)
4. What is a regular expression and how do I compose one?
5. How do I automate the collection of data from the web on a schedule to compile data over time?

You can write a script and set up a scheduled task (e.g., in "cron"), which can append it's output to a CSV file.

6. What are the most important Tidyverse functions and packages and how/when do I use them?
7. How do I write portable code that won't break if someone else tries to run it?
8. How do I create a Markdown file from a regular script? (Or the other way around.)
9. How do I avoid copying and pasting code if I want to repeat something with slight variations?
10. How do I combine the results of outputs from functions like summary (of lm, glm, etc.) run multiple times into a single data set?
11. Coding is hard/scary/time-consuming/tedious. How do I become more confident/proficient?
12. I am about to graduate. What language/skill/technology should I learn to help me get a good job?
13. What do all of those "apply" functions do and how do I use them?
14. What is a "tidy" dataset and how do I create one?
15. Why won't this code I got from someone else run on my computer?
16. What is a "list" and how do I convert it to a data frame?
17. I've taken several courses that use R. Why am I not getting any better at it?
18. Why doesn't this work? (This is the #1 question, really. It leads to most of the others.)