[R] Nested variables

[Douglas Bates]

On Fri, May 29, 2009 at 7:50 AM, DanielWC <daniel.carstensen at gmail.com> wrote:

> Hello
> I am working with a biological data including variables called Habitat and
> Site, example:

> Habitat     Site

> Forest      Low
> Forest      Low
> Forest      High
> Forest      High

> I want to tell R that the Site variable is nested within the Forest variable
> (that it is not a new variable).
> Does anyone know how to do this?

If you could explain what you mean by "tell R", it would help.  Are
you trying to model such data and you want to know how to express the
relationship between such factors in a model formula?