Using Noir and incanter

gistfile1.clj

(ns simple_server
  (:gen-class)
  (:use  [noir.server :only (start load-views)]) 
 )

(load-views "src/simple_web_app")

(defn -main [& m]              
  (let [port (Integer. (get (System/getenv) "PORT" "8080"))]
    (start port {:mode :dev :ns 'stats-web})))

incanter-webui.clj

# an updated version of http://data-sorcery.org/2009/11/29/incanter-webapp/

(ns simple_web_app
  (:use 
    [noir.response :only (content-type)]
    [noir.core :only (defpage)]
    hiccup.core 
    hiccup.form-helpers
    [incanter core stats charts])
  (:import (java.io ByteArrayOutputStream 
                    ByteArrayInputStream)))


;; Pass a map as the first argument to be 
;; set as attributes of the element
(defn html-doc 
  [title & body] 
  (html 
    [:html 
     [:head 
      [:title title]] 
     [:body 
      [:div 
       [:h2 
        [:a {:href "/"} 
         "Generate a normal sample"]]]
      body]])) 


(def sample-form 
  (html-doc "sample-normal histogram" 
            (form-to [:post "/sample-normal"] 
                     "sample size: " (text-field {:size 4} :size) 
                     "mean: " (text-field {:size 4} :mean) 
                     "sd: " (text-field {:size 4} :sd) 
                     (submit-button "view")))) 



(defn gen-samp-hist-png 
  [size-str mean-str sd-str] 
  (let [size (if (nil? size-str) 1000 (Integer/parseInt size-str))
        m (if (nil? mean-str) 0 (Double/parseDouble mean-str))
        s (if (nil? sd-str) 1 (Double/parseDouble sd-str))
        samp (sample-normal size :mean m :sd s)
        chart (histogram samp :title "Normal Sample"
                         :x-label (str "sample-size = " size 
                                       ", mean = " m 
                                       ", sd = " s))
        out-stream (ByteArrayOutputStream.)
        in-stream (do
                    (save chart out-stream)
                    (ByteArrayInputStream. 
                      (.toByteArray out-stream)))
        header {:status 200 :headers {"Content-Type" "image/png"}}]
    {:headers {"Content-Type" "image/png"} :body in-stream}
    ))

(defpage "/" [] sample-form)

(defpage [:post "/sample-normal"] {:as params}
  (gen-samp-hist-png (params :size) (params :mean) (params :sd)))