[R] Vaseplots

[Liaw, Andy]

I don't have that article handy, but it sounds like `violin plots' that I've
read (also in Am. Stat.) quite a while ago.  I wrote a S-PLUS function to do
something like it back in the dark ages.  It probably isn't too hard to
modify for use with R.  See if it does something similar:

violin.plot<-function(y, x=NULL, ...) {
    if (is.null(x)) {
        cx <- boxplot(y,style.bxp='old')
        den.y <- ksmooth(y,ker='n')
        polygon(c(cx+40*den.y$y,cx-40*rev(den.y$y)),
                c(den.y$x,rev(den.y$x)),...)
    } else {
        if (!is.factor(x)) x<-factor(x)
        cx <- boxplot(split(y,x),style.bxp='old')
        lev.x<-levels(x)
        wd<-45/length(lev.x)
        for(i in 1:length(lev.x)) {
            den.y<-ksmooth(y[x==lev.x[i]],ker='n')
            polygon(c(cx[i]+wd*den.y$y,cx[i]-wd*rev(den.y$y)),
                    c(den.y$x,rev(den.y$x)),...)
        }
    }
}

[Note that I had to do quite a bit of fudging to get the x-coordinates sort
of right in S-PLUS.  In R this is a LOT easier.]

Andy

> From: Peter Flom
> 
> In The American Statistician vol 42 (1988) pages 257 - 280, Yoav
> Benjamini investigates some variations on the box plot, including
> vaseplots, which maek the width of each box vary proportionally to he
> estimated density at a particular point.
> 
> Has anyone implemented these in R ?
> 
> Thanks as always
> 
> Peter
>