ST Intro to R programming Big picture language features -- just a brief description here -- more later:

Interpretive R translates symbols (e.g. x, 2.53, *, qr) into numbers, variables, and other expressions which are evaluated immediately (almost)

Object-oriented "everything is an object" Well, that really doesn't say anything. But as I see it, if a function takes a certain kind of object -- as long as R can recognize it or force into something it can recognize, then a function will work -- and produce another object, for another function or expression to work with. Variables, constants, and functions are all objects.

Coercion R will instinctively try to make sense of any expression that you give it, even if to you it is nonsense. So this can be very dangerous, as R will proceed many times when you would prefer that it would stop processing for syntax errors.

Recycling When R is trying to coerce something to work, and it needs more numbers, it will instinctively reuse the numbers that it has. For example, if you try to add a constant to a vector, R will really take the constant and make a vector of the same length as the other with it, by repeating the single number that it has. While very powerful, this can also be dangerous.

Lexical Scoping The real power of R is in its functions, and R creates a new working environment with each instance of a function. Variables are referenced (scoping) according its nested environment structure.

Natural and unnatural looping R is designed to do vector/matrix calculations and works best when calculations are coded to that end. R does have a loop feature (for loop) which can be competitive in speed to its natural looping, but more often is slow and inefficient.

Some Details gui vs batch and directory reference source("infile.name") sink("outfile.name") and sink() to discontinue.RData and.Rhistory help(command) q() to stop # begins a comment that continues to the end of the record