directlabels - densityplot - Positioning Method - top.bumptwice

Label the tops, bump labels up to avoid other labels, then to the side to avoid collisions with points.

top.bumptwice <- function(d,debug=FALSE,...){
  labtab <- apply.method("top.bumpup",d)
  if(debug)draw.rects(labtab)
  gapply(labtab,function(l,...){
    between <- d[d$y>l$bottom & d$y<l$top,]
    x <- sort(c(range(d$x),between$x))
    if(length(x)==2)return(l)
    dif <- diff(x)
    ok <- dif>with(l,right-left)
    if(!any(ok))ok[1] <- TRUE
    i <- which(ok)
    intervals <- data.frame(left=x[i]+l$w/2,right=x[i+1]-l$w/2,i=seq_along(i))
    molt <- with(intervals,data.frame(i,x=c(left,right)))
    dists <- transform(molt,dist=x-l$x)
    best <- dists[which.min(abs(dists$dist)),]
    besti <- intervals[best$i,]
    l$x <- if(l$x<besti$right & l$x>besti$left)l$x else best$x
    l
  })
}

	chemscore data(Chem97,package="mlmRev") library(lattice) p <- densityplot(~gcsescore|gender,Chem97, groups=factor(score),layout=c(1,2), n=500,plot.points=FALSE) direct.label(p,"top.bumptwice")
	iris library(reshape2) iris2 <- melt(iris,id="Species") library(lattice) p <- densityplot(~value|variable,iris2,groups=Species,scales="free") direct.label(p,"top.bumptwice")
	loci loci <- data.frame(ppp=c(rbeta(800,10,10),rbeta(100,0.15,1),rbeta(100,1,0.15)), type=factor(c(rep("NEU",800),rep("POS",100),rep("BAL",100)))) library(ggplot2) p <- qplot(ppp,data=loci,colour=type,geom="density") direct.label(p,"top.bumptwice")