[R] Re : Re : Adding mean line to a lattice density plot

[Petr PIKAL]

Hi

> HI again,
> 
> thanks for the replies. Unfortunately, due to my deadlines, I had no 
> time to test Petr's suggestion. I will test it later. I had to figure 
> out an alternate solution, so I decided to use "normal" plotting 
functions:
> 
>  > with(subset(ISGFINC2, as.numeric(SGENDER)==1), plot(density(PV1CIV),
>    lwd=2, lty=1, ylim=c(0,.006)))
>  > with(subset(ISGFINC2, as.numeric(SGENDER)==2), lines(density(PV1CIV),
>    xlab="", lwd=2, lty=2))
>  > abline(v=mean(ISGFINC2$PV1CIV[ as.numeric(ISGFINC2$SGENDER)==1 ],
>    na.rm=T), col=2, lwd=2, lty=1)
>  > abline(v=mean(ISGFINC2$PV1CIV[ as.numeric(ISGFINC2$SGENDER)==2 ],
>    na.rm=T), col=2, lwd=2, lty=2)

Basically after lattice plot you could do

addLine(v=mean(ISGFINC2$PV1CIV[ as.numeric(ISGFINC2$SGENDER)==2 ], 
na.rm=T), col=2, lwd=2, lty=2)

if you want one vertical line in each panel.

If you want different vertical lines in each panel you must set once to 
TRUE and provide a vector of values for vertical lines.

Regards
Petr 

> 
> This command sequence produced the plot I was looking for. But since the 

> lattice package offers several options not available in "normal" 
> plotting, I am still interested in understanding how to add elements in 
> a lattice/trellis plot.
> 
> Kind regards,
> Kimmo
> 
> 08.03.2012 16:53, Petr PIKAL wrote:
> > Hi
> >
> > You can use this function to add arbitrary line to already plotted 
lattice
> > graph.
> >
> > addLine<- function(a=NULL, b=NULL, v = NULL, h = NULL, ..., once=F) {
> > tcL<- trellis.currentLayout()
> > k<-0
> > for(i in 1:nrow(tcL))
> >    for(j in 1:ncol(tcL))
> >      if (tcL[i,j]>  0) {
> > k<-k+1
> >          trellis.focus("panel", j, i, highlight = FALSE)
> > if (once) panel.abline(a=a[k], b=b[k], v=v[k], h=h[k], ...) else
> > panel.abline(a=a, b=b, v=v, h=h, ...)
> >          trellis.unfocus()
> >          }
> > }
> >
> > the usage is similar to abline in base graphics.
> >
> > addLine(h=some number)
> >
> > Regards
> > Petr
> 
> ______________________________________________
> 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.