[R] sorting Trellis panels

Can anyone explain how to properly use index.cond? I cannot include it in the xyplot command and get what I expect. For example, plot<-xyplot(y ~ x | z, data) # let's say z is a factor with six levels gives a nice plot but I am unhappy with the order of panels. I can get the order I w

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

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(filei