(See notice at the end of this document regarding copyright.) This site is for those who know nothing of R, and maybe even nothing of programming, and seek QUICK, PAINLESS! entree to the world of R.

When you count to 20, you start at 1 (or zero) and count on until you reach 20. Each number is one more than the last. When you count back from 20, you start at 20 and count back until you reach 1 (or ...