[R] Alpha values

[Prof Brian Ripley]

Yes, but currently only alpha=0 and alpha=255 are supported by the
available devices that I know of (and I introduced this).

Adding alpha-level support is complicated for the devices people normally
use, although it would be trivial in PDF1.4.

On Wed, 12 Nov 2003, Crispin Miller wrote:

> Does anyone know whether it is possible to construct a colour for
> plotting with an alpha value as well as simply specifying rgb values?

-- 
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