Re: [R] highlighting subset of point with xyplot (or Hmisc(xYplot))

From: Deepayan Sarkar <>
Date: Sat 17 Jul 2004 - 07:42:21 EST

On Friday 16 July 2004 16:32, Patrick Lorch wrote:
> Hello all,
> I am trying to use xyplot to give a six panel plot and to highlight
> only points (in any panel) that meet a certain criterion. With the
> plot command I would do something like:
> plot.default(filein$Site,filein$circ.conc)
> points(filein$Site,filein$circ.conc,type="p",
> pch=ifelse(filein$p.value<5e-02,19,21))
> I had thought I could just stick in the pch line from above into either
> xyplot or xYplot with groups set to Site like:
> xyplot(circ.conc~Day|Site,data=allsites.byday,groups=Site,
> pch=ifelse(allsites.byday$p.value<5e-02,19,21))
> This does not produce any highlighting (all symbols come out as open
> circles (19)). I have not messed with writing my own panel functions,
> though I know that is where the solution must lie. Hopefully someone
> has an example that is close enough to help me. I can send an example
> plot to anyone that wants one.

It's difficult to check without data, but I believe the following would work:

xyplot(circ.conc ~ Day | Site, data=allsites.byday,

       ## groups=Site, I don't see the point of this
       groups = p.value<5e-02, 
       pch = c(19, 21))

Note that I have removed the original groups variable, because I don't see a point in having that (since Site is already used as a conditioning variable). If you really need another grouping variable, then this would become slightly more complicated.

Deepayan mailing list PLEASE do read the posting guide! Received on Sat Jul 17 07:54:10 2004

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