Understandable documentation about R?

Question

Does there exist understandable Free documentation for the R programming language, which is accessible to statistics-impaired people?
The ideal documentation would include also motivation (an example) for using each statistical function.

Answer 1

I found that the following http://www.cyclismo.org/tutorial/R/ was quite useful at a very basic level.

It also includes a couple of case studies.

Answer 2

The R documentation is actually pretty good, it's just strange for people with a non-Unix background and takes some getting used to. If you wonder about the statistical background, then I suggest searching the names of the statistical functions/tests in Wikipedia. I've done this a lot, with generally good results.

Two examples:

• T test
• Uniform distribution

Answer 3

If you want general overviews of the R library, the

help.start()   ## opens a browser instance with the R docs

command is very useful, as is

?command_name
help.search("someterms")

I agree with other commenters that some of it will be a hard slog if you don't know statistics.

Answer 4

You almost have to think like a statistician before R will make any sense. It's not that you have to know statistics at a mathematical level, it's that you have to put yourself in the shoes of someone interactively exploring a data set. Some of the features of the language are absolutely bizarre if you're expecting it to behave like a system programming language. But the same features make more sense if you think like a statistician.

Here are my notes on R, things I found most surprising coming from mainstream programming languages.

Answer 5

Yes R is hard! I'm a .net programmer who knows a fair bit about statistics (used to be a biologist), which means I sometimes get lumbered with R scripts from the statisticians and have to try and lever them into our projects. I still don't think I properly understand things like variable name assignment :-o

R works alot on vectors/arrays of info, but sometimes arrays can hold other arrays etc. and trying to sort the mess out can be frustrating. I'm sure that if an R expert saw my R code it would end up on The Daily WTF!

I usually resort to the R forums on Nabble (http://www.nabble.com/R-f13819.html) for help, all the R geeks hang out there!

Answer 6

There are some great free books about R. One in particular I would recommend is:

"Statistics Using R with Biological Examples” by Kim Seefeld and Ernst Linder

That book and others are listed here: http://cran.r-project.org/other-docs.html