Re: [R] dotplot (lattice) with panel.segments and groups

From: Deepayan Sarkar <>
Date: Sat 08 Jul 2006 - 05:57:10 EST

On 7/7/06, Gabor Grothendieck <> wrote:
> Could you explain what panel.groups= does and what the difference
> is between panel.groups= and panel= ? In ?xyplot it just says:
> panel.groups: useful mostly for 'xyplot' and 'densityplot'. Applies
> when 'panel' is 'panel.superpose' (which happens by default
> in these cases if 'groups' is non-null)
> which indicates when it might apply but not what it does.

That's wrong (it used to be right - a good example of why \synopsis is bad). Since lattice 0.13-x, panel.superpose is never the default panel function. An updated version with improved documentation should be out soon.

'panel.groups' is simply an argument to panel.superpose, and is described in ?panel.superpose. Thus, it only makes sense as an argument to xyplot/dotplot/whatever when the panel function is panel.superpose, and not otherwise. The entry for the graphical parameters in ?panel.superpose isn't as useful as it could be, I have just updated it to read:

col, col.line, col.symbol, pch, cex, fill, font, fontface, fontfamily, lty, lwd, alpha: graphical

          parameters, replicated to be as long as the number of
          groups.  These are eventually passed down to 'panel.groups',
          but as scalars rather than vectors.  When 'panel.groups' is
          called for the i-th level of 'groups', the corresponding
          element of each graphical parameter is passed to it.

Hope that makes things a bit clearer.

Deepayan mailing list PLEASE do read the posting guide! Received on Sat Jul 08 07:11:34 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Sat 08 Jul 2006 - 08:15:29 EST.

Mailing list information is available at Please read the posting guide before posting to the list.