[R] RGB -> CYMK, with consistent colors

[Derek Jones]

Martin,

>> Have you tried printed a few pages in CMYK?
>>
>> A monitor is based on mixing light using Red-Green-Blue. So it is not
>> possible for the monitor to show
>> CMYK which must be printed on paper to view correctly.
> 
> Yes, I have printed some 'CMYK' pages.
> 
> The blue is very obviously not cyan, as compared to printing the
> RGB version.

Let me correct the last sentence.
The printed blue is obviously not cyan when printing 'rgb' and 'cmyk'
pages.

Somebody pointed out in an email that probably I am the only one who
is going to notice the difference, and he may be right.

My frustration is that the printer supports cyan as a base color.
I understand that rgb->cmyk involves lots of variables, and I'm hoping
that somebody will point me at one that allows me to tweak the output.

library("colorspace")

two_c=rainbow(2)

x=runif(20)
y=runif(20)

plot(x, y, col=two_c[2])


pdf(file="cmyk.pdf", colormodel="cmyk")
plot(x, y, col=two_c[2])
dev.off()