cprop <- function(x) { prop <- x/sum(x) cumsum(prop) } prop <- function(x) { x/sum(x) } spine <- function(x) { px <- prop(x) cpx <- cprop(x) grid.rect(y=cpx, height=px, just="top") } connector <- function(x1, x2) { cp1 <- cprop(x1) cp2 <- cprop(x2) grid.segments(0, cp1, 1, cp2) }