Fig5.7s <- function()
{
#  postscript(file = "Fig5.7.ps", height = 3.9, width = 6.5, horiz = F)
  par(mar = c(1.5, 1.5, 1.5, 0.5), mgp = c(5, 0.4, 0))
  doppler <- make.signal("doppler", n = 1024)
  plot((1:1024)/1024, doppler, type = "l")
#  graphics.off()
  NULL
}