[R] dev.print and X11(canvas = "black")

[Prof Brian Ripley]

On Tue, 2 Mar 2004, Jeffrey J. Hallman wrote:

> Jim Lemon made essentially the same suggestion: run the code that
> created the plot twice, once with X11 as the active device, and again
> with postscript as the active device.
> 
> The trouble with this is that is doesn't handle plots that the user has
> edited.  I have some charts that users add things to interactively,
> using combinations of locator(), text(), mtext(), and arrows().  There's
> no nice way to know what a user has done to a plot before he attempts to
> print it.

Yes, see the sections on `Graphics hardcopy' in section A.1 of MASS4 for 
exactly this comment: it is hardly news.

You could record what the users do as they do it by using your own 
versions of these functions.

> I know that R is internally maintaining a display list.  Is there a way
> to access that without dropping into C?  And what's in it, anyway?

Not really (recordPlot etc does), and not documented AFAIK (but Paul
Murrell will be able to correct me if I am wrong here).  However, I am
pretty sure that it has the actual plot colours and not the colour numbers
in it.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595