RDX2 X  qqthin source( :function(x, y, ends=c(.01,.99), eps=0.001, plot.it = TRUE, * xlab = deparse(substitute(x)),  9 ylab = deparse(substitute(y)), show.line=TRUE, ! centerline=TRUE, ...){ 8 ## qqthin() is a substitute for qqplot(), that thins 8 ## out plotted points from the region where they are 7 ## dense. Apart from the overlaid curve that shows 8 ## the region where points have been thinned, it may 4 ## be hard to distinguish the result of qqthin()  ## from that of qqplot()  x <- sort(x)  y <- sort(y)  dx<-diff(x) : epsdist <- sqrt(diff(range(x))^2+diff(range(y))^2)*eps . dx<-0.5*(c(dx[1],dx)+c(dx,dx[length(dx)]))  dy<-diff(y) . dy<-0.5*(c(dy[1],dy)+c(dy,dy[length(dy)])) & dpoints <- epsdist/sqrt(dx^2+dy^2) 9 ## dpoints is a local measure of the number of points : ## per unit distance along the diagonal, with the unit 4 ## set to approximately eps*(length of diagonal)  dig<-floor(dpoints)+1 ? ## dig is, roughly, the number of points per unit distance. ? ## We wish to retain one point per unit distance. For this > ## retain points where cdig rounds to an integer. For such > ## points, cdig has increased by approx 1, relative to the ' ## previous point that is retained.  cdig<-round(cumsum(1/dig)) # subs<-match(unique(cdig), cdig) 0 plot(x[subs], y[subs], xlab=xlab, ylab=ylab) & n1 <- min(subs[c(diff(subs),0)>1]) & n2 <- max(subs[c(0,diff(subs))>1])  ns1 <- match(n1, subs)  ns2 <- match(n2, subs) : print(paste("Graph retains", length(subs), "points."))  if(centerline) > lines(smooth.spline(x[subs[ns1:ns2]], y[subs[ns1:ns2]]),  col="grey", lwd=2) ( if(show.line)abline(0, 1, col="red")  }þý xû yû ends c?„záG®{?ï®záG®þ eps?PbMÒñ©ü plot.it $ xlab deparse substituteÿþþ$ ylab ÿ ÿÿþþ show.line  centerline  ...ûþ { <-ÿ sortÿþþÿÿÿÿþþÿ dx diffÿþþÿ epsdist * sqrt + ^ÿ rangeÿþþ@þÿÿÿÿþþ@þþþÿþþÿÿÿ?à (ÿÿ [ÿ?ðþÿþÿÿÿÿ lengthÿþþþþþþþÿ dyÿÿþþÿÿÿ?àÿÿÿÿÿ?ðþÿþÿÿÿÿÿÿþþþþþþþÿ dpoints /ÿÿÿÿÿ@þÿÿ@þþþþþÿ digÿ floorÿþ?ðþþÿ cdig round cumsum ÿ?ð!ÿþþþþÿ subs match unique#ÿþ#ÿþþ plotÿÿ&ÿþÿÿ&ÿþ ÿ ÿ ÿ ÿþÿ n1 minÿ&ÿ >ÿÿ&ÿþþ?ðþþþþÿ n2 maxÿ&ÿ,ÿÿÿ&ÿþþ?ðþþþþÿ ns1'ÿ*ÿ&ÿþþÿ ns2'ÿ-ÿ&ÿþþ print paste Graph retainsÿ&ÿþ points.þþ ifÿ lines smooth.splineÿÿÿ&ÿ :/ÿ0ÿþþþÿÿÿ&ÿ6ÿ/ÿ0ÿþþþþ col grey lwd@þþ3ÿ ÿ abline?ð7ÿ redþþþþ