[R] NA values for "col"

[Rolf Turner]

On Mon, 27 Sep 2021 14:54:53 -0700
Bert Gunter <bgunter.4567 using gmail.com> wrote:

> ... and also note in the *Color Specification* section of ?par, to
> which ?points points,
> 
> "Additionally, "transparent" is transparent, useful for filled areas
> (such as the background!), and just invisible for things like lines or
> text. In most circumstances (integer) NA is equivalent to
> "transparent" (but not for text and mtext)."
> 
> So an NA specification for col (or part of col, if a vector) plots the
> point in "transparent" rather than omitting it.
> 
> Now if your question is *why* the specifications for a color of NA are
> different in points() and text(), I don't have a clue. But the
> difference is documented.

Thanks Bert.  Clear enuff!

cheers,

Rolf

-- 
Honorary Research Fellow
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276