[R] Lattice: panel superpose with groups

[Deepayan Sarkar]

On 9/4/07, Folkes, Michael <FolkesM at pac.dfo-mpo.gc.ca> wrote:

> Thank you again Deepayan.  I was failing to grasp that I could use
> panel.groups as a function.  But additionally it's still not intuitive
> to me where and when I should use "..." to pass arguments on.

In most cases, it's used to pass on graphical parameters, so I tend to
have the ... by default (which means you can supply graphical
parameters directly as arguments to xyplot). This is particularly
non-trivial in panel.groups, because panel.superpose does a lot of
work to replicate the parameters and pass on a different one for each
call to panel.groups.

> Additionally, as to why the panel.group function needs to pass the 'lty'
> argument isn't terribly clear to me!

Try not having it and you will find out. Basically, if you don't have
it, the explicit lty=3 in the call to panel.abline will conflict with
the lty passed on through ...

-Deepayan