Learning R. Where does one Start? [closed]

Question

I've been using R for a little over a year now and it's been a successful venture. But all too often, I find that there is something that I can't figure out for lack of knowing how to find it or an example of it.

Stackoverflow,

Could you recommend a pathway for learning R in a manner that provides one with a toolset at their disposal to solve problems of a statistical nature?

There's a wealth of knowledge on the internet, between the r-project website and the mailings lists but it seems to be "everywhere" and nowhere when you're actually looking for it.

For example, when I first started using R, I went through "Intro to R". Then I read the language definition (which obviously hasn't sunk in). But every time I ask a question on Stackoverflow I'm presented with some new badass function that is the solution to all my problems in the short term. My question is, how did you know these functions existed in the first place? And how does one go about finding them? Presumably, you read something or found some resources that detoured your learning to the exponential part of the curve. What was it?

Obviously, R's functionality as a statistical tool is broad. For my own purposes I work mostly with economic or financial data. Hence, answers with this in mind would be most helpful.

Answer 1

Completely biased response: learn plyr, reshape2 and ggplot2. They will cover 90% of your data manipulation and visualisation needs. All three packages have a consistent philosophy of data (which the ggplot2 book touches upon), and are designed to be consistent and easier to learn.

Rather than learning many specialised functions, I really encourage you to learn about simple functions that can be flexibly composed to solve a wide range of problems. This is what plyr strives to do for data manipulation, and what ggplot2 strives to do for visualisation. It does mean you need to invest more time up front to learn a little about the underlying theory, but it's my belief that it will pay off handsomely in the long run.

Answer 2

My way how I learned R.

R resources:

• To learn R, the most important resource is google. search for: “TOPIC r-project”, “TOPIC filetype:r”, or “TOPIC site:nabble.com”.

• Second, look at the example code provided with most packages. go to “http://bm2.genes.nig.ac.jp/”, search for a topic and look at the example code. run it and adapt it, this way you can often solve part of your problem.

• Third: the r-help mailing list. Read the posts, the basic questions get asked over and over again. If you have a problem and you are completely stuck, ask a question on the mailing list.

• Finally, look at the source code of the R-packages. that’s the hardest part. if you can alter the code to your needs, you have mastered R ;-)

Some Tips:

• R has a steep learing curve. that’s a feature ;-) , it is designed to solve advanced problems and in the end you are fast than when using an alternative to R.

• Know every single R package and function that is relevant to your problem. the strength of R is that there are so many packages availiable (around 2000, I think). Usually there is always a package that’s more suited or that already solves your problem. (some help pages are badly written and hard to understand - I got used to it)

• R books are not helpful in learning R. yes, that’s true. If you are an expert programmer and expert statistician, you don’t need any book on R. (only exception is Hadley Wickham’s ggplot2 book). If your are not, learn programming in general and/or advanced statistics.

• Some R package have known bugs, which nobody will fix (package owner left university, etc.). just a warning, this can be tricky if you are looking for a bug in your code and the bug is in a R package.