geotheory

require(raster)
require(ggplot2)

pulsar = function(n){
  x = seq(0,100, length=n)
  norms = dnorm(x, mean=40, sd=6)*100 + dnorm(x, mean=60, sd=6)*50
  noise1 = approx(sample(c(rep(0:8,2),18:19)), n = n, y=NULL)$y
  noise2 = approx(sample(0:50), n = n, y=NULL)$y
  noise3 = rnorm(n)
  abs(norms + norms * noise1 + norms * noise2 * .1 + noise3)