[Rd] using a factor as col argument in plot:

[Christoph Buser]

Dear R core team

Using the following code produces an empty plot (similar 
to col = NA): 

> plot(1:9, col = factor(rep(1:3,3), labels = c("red", "blue", "black")))


My question: Shouldn't one get at least a warning (or an error)
	     if one tries to use a factor as col argument?

Thanks for an answer.

Regards,

Christoph Buser

--------------------------------------------------------------
Christoph Buser <buser at stat.math.ethz.ch>
Seminar fuer Statistik, LEO C13
ETH (Federal Inst. Technology)	8092 Zurich	 SWITZERLAND
phone: x-41-44-632-4673		fax: 632-1228
http://stat.ethz.ch/~buser/