[R] Calling symbols from dataframe for xyplot

[Greg Snow]

The more common way to do this is to use groups, the default is to have a different color for each group, but you can change that using trellis.par.set:


tmp <- trellis.par.get()
tmp$superpose.symbol$pch = 0:10
trellis.par.set(tmp)
xyplot(Sepal.Width ~ Petal.Width, data=iris, groups=Species, auto.key=TRUE)


If you need more control of the symbols than that, then look at the panel.my.symbols function in the TeachingDemos package.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of John Poulsen
> Sent: Thursday, February 10, 2011 2:22 PM
> To: r-help at r-project.org
> Subject: [R] Calling symbols from dataframe for xyplot
> 
> Hello,
> 
> I am trying to make a xyplot plot with points that are different
> symbols. I want to call the symbol type (pch) from a column in my
> dataframe.  Here is a simplified example.  In my real example I also
> have groups, which I have not included here.  This example doesn't
> change the symbols or colors.
> 
> Any help you can provide would be appreciated.
> 
> Thanks,
> John
> 
> x<-c(1:12)
> y<-c(rpois(12,4))
> grp<-c(rep(c(3,4), each=6))
> z<-c(rep(c(1,2), each=6))
> p<-rep(1:3,4)
> 
> xyplot(y~x|z, cex=1.2,
>        panel=function(x,y,...){
>        	 panel.xyplot(x,y,...)
>        	  pch=p
>        	  fill=list("black","blue")})
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.