Learning R. Where does one Start? [closed]

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.

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.