[R] RGB -> CYMK, with consistent colors

[Derek Jones]

Martin,

> However after some testing.
> I totally agree that CMYK handling in R using pdf(..., colormodel = "cmyk")
> is not correct.

I thought the issue may be OS specific, but I get similar behavior on a Mac.

I have discovered the Cyan tool: http://cyan.fxarena.net/
and will try it out.

As various people have pointed out, RGB -> CMYK conversion is never going
to be perfect.  It just so happens that my book contains many plots that use
red and cyan, and a good conversion to cyan is most of what I am after.

 > One solution:
 > Output in tiff or png instead and then convert to CMYK using external tools.

There are 600+ figures.  There are png versions here:
http://knosof.co.uk/ESEUR/figures/index.html