#randomizer for minPD, rich =vector of commuity richness, or just max and min
#Marc Cadotte
#Nov 2008

randMinPD<-function (phy,rich,nsamp=1000) {

	r.levels<-c(min(rich):max(rich))
	species<-phy$tip.label
	min.r<-NULL
	rand.r<-data.frame(r.levels=NULL,min.r=NULL)
	
	for (j in 1:nsamp) {

		r.tmp<-NULL

		for (i in 1:length(r.levels)) {
	
			sp.tmp<-sample(species,r.levels[i])
			dropme<-species[!species %in% sp.tmp]
			sub.tree<-drop.tip(phy,dropme)
			dm<-(cophenetic(sub.tree))
			r.tmp[i]<-min(dm[lower.tri(dm,diag=F)])
			}

		rand.tmp<-data.frame(r.levels,min.r=r.tmp)

		rand.r<-rbind(rand.r,rand.tmp)
	
	}
	return(rand.r)
}