Top Ten Questions from New R Users
1. How do I use probability distributions in R? Answer from RWiki.
2. How can I speed up loops in R? An answer from R Revolutions.
4. What is a good package to use to manipulate strings in R? My favorite package is stringr for working with strings in R.
5. What are the different types of data structures in R? Find a great answer here.
7. How do I generate random numbers in R? An answer from R Revolutions.
8. How do I run regressions in R? Check out this answer from Quick-R.
9. How do I deal with dates in R? An answer from the UCLA tutorial on R.
Fun things to do after you learn the basics:
Basic web-scraping in R: Useful because sometimes you want to get data directly from a table on a website, but there is no way to download the current data into a readable file. Also check out webscraping using R Curl and readLines.
TwitteR: scrape twitter using R!
Two ways to do genetic matching in R: This code snippet shows two ways of implementing genetic matching in R. The first method uses the GenMatch() package, and the second uses MatchIt(). Essentially, this is a template to show how you can set your covariates and extract the treated or control data. Note that with the MatchIt() package, you could implement various other matching methods by specifying e.g. "nearest" rather than "genetic."
Kountry: A R and Stata package for dealing with annoying country codes
R Benchmark: Package to help benchmark code in R.