options(digits=, expressions=, width=, prompt=,
continuation=, editor=)
digits controls the number of digits to print when printing
numeric values. It is a suggestion only. expressions sets
a limit on the number of nested expressions that will be evaluated.
This is especially important on the Macintosh since stack overflow
is likely if this is set too high.
width controls the number of characters on a line. You may
want to change this if you resize the window that R is running in.
prompt must be a quoted string. The expression inside the
quotes will be used for the prompt. continuation must be a
quoted string. It sets the prompt used for lines which continue
over one line. editor sets the default text editor. Invoking
options returns a list with the current values of the options stored
in it.