(require (planet "poisson.ss" ("williams" "science.plt")
                 "random-distributions"))
(require (planet "histogram-with-graphics.ss"
                 ("williams" "science.plt")))

(let ((h (make-histogram-with-ranges-uniform 21 0 20)))
  (do ((i 0 (+ i 1)))
      ((> i 20) (void))
    (histogram-accumulate! h i (poisson-pdf i 10.0)))
  (histogram-plot h "Poisson Distribution"))