gamma_pdf.clj

;; Examples of plots from the Gamma Distribution page at
;; Wikipedia (http://en.wikipedia.org/wiki/Gamma_distribution)

(use '(incanter stats charts io))

(def x (range 0 20 0.1))
(def gamma-plot (xy-plot x (pdf-gamma x :shape 1 :rate 2) 
                           :legend true
                           :title "Gamma PDF"
                           :y-label "Density"))
(view gamma-plot)
(add-lines gamma-plot x (pdf-gamma x :shape 2 :rate 2))
(add-lines gamma-plot x (pdf-gamma x :shape 3 :rate 2))
(add-lines gamma-plot x (pdf-gamma x :shape 5 :rate 1))
(add-lines gamma-plot x (pdf-gamma x :shape 9 :rate 0.5))
(clear-background gamma-plot)
(save gamma-plot "/tmp/gamma_pdf.png")