Adding Histograms and Density plots to a splom

Unfortunately just using panel.histogram or panel.densityplot does not work. The issue was discussed on R-help in August/September 2007. In August Deepayan Sarkar offered this suggestion for adding a density plot: 
splom(USArrests, diag.panel = function(x, ...) {
    yrng <- current.panel.limits()$ylim
    d <- density(x)
    d$y <- with(d, yrng[1] + 0.95 * diff(yrng) * y / max(y) )
    panel.lines(d)
})
In September Benjamin Barnes suggested this modification to show histograms: 
panel.hist.splom<-function(x, ...) {
    yrng <- current.panel.limits()$ylim
    h <- hist(x, plot = FALSE)
    breaks <- h$breaks
    nB <- length(breaks)
    y <- h$counts
    y <- yrng[1] + 0.95 * diff(yrng) * y / max(y)
    panel.rect(breaks[-nB], yrng[1], breaks[-1], y, col="cyan", ...)
}
splom(USArrests, diag.panel = panel.hist.splom)

Luke Tierney 2008-09-18