[R] PLotting R graphics/symbols without user x-y scaling

[Jonathan Lees]

Is it possible to add lines or other
user defined graphics
to a plot in R that does not depend on
the user scale for the plot?

For example I have a plot
plot(x,y)
and I want to add some graphic that is
scaled in inches or cm but I do not want the
graphic to change when the x-y scales are
changed - like a thermometer, scale bar or
other symbol -
How does one do this?

I want to build my own library of glyphs to add to plots
but I do not know how to plot them when their
size is independent of the device/user coordinates.

Is it possible to add to the list
of symbols in the function symbols()
other than:
  _circles_, _squares_, _rectangles_, _stars_, _thermometers_, and
      _boxplots_

can I make my own symbols and have symbols call these?


Thanks-


-- 
Jonathan M. Lees
Professor
THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL
Department of Geological Sciences
Campus Box #3315
Chapel Hill, NC  27599-3315
TEL: (919) 962-0695
FAX: (919) 966-4519
jonathan.lees at unc.edu
http://www.unc.edu/~leesj