Usually in R, to find help about something, you have to know it exists to begin with. Since I have discovered numerous useful functions in R by happenstance, I thought I would pass them along. I have tried to give categorized lists of useful functions. Some of them are obvious and well-known, but others are not. These are clearly not exhaustive. These are just lists to give a starting point. To learn what the functions do, some commands have html links (which may not all be quite correct...) to R help pages or just use help within R (links to R help pages hosted by Lund Centre for Mathematical Sciences)