Display Lists in R

Paul Murrell and Ross Ihaka

A display list is a record of the drawing operations used to produce a
picture.  A display list can be used to refresh an on-screen picture
or to copy a picture from, say, the screen to a file format like PDF.

A display list differs from something like a "backing store", which 
is only a record of the *output* of drawing operations, because a 
display list works at a higher level, capturing a *description* 
of what has been drawn.

This talk will discuss the fact that there are several levels at 
which a display list can work, explain why the initial implementation of
display lists in R is too low, describe an augmentation of the
display list mechanism in R which is higher, and demonstrate some
examples where higher is better and other examples where higher is worse.