an example of plotting route in XY-coord with Clojure/quil

plot-route.clj

;; an example of plotting route in XY-coord with Clojure/quil

(require '[quil.core :as q])

(def sample-points
  {:a [20 70] :b [30 20] :c [50 50] :d [60 59] :e [40 30]
   :f [20 50] :g [80 60] :h [10 30] :i [65 10] :j [40 80]})

(def route [:a :f :j :d :g :i :c :e :b :h])

(defn drop-colon [point]
  (apply str (rest (vec (str point)))))

(defn draw-route [points route]
  (let [base-x 30 base-y 30 reversed-y 370 mag 3.5 circle-r 15
        set-white #(q/fill (q/color 255))
        set-blue #(q/fill (q/color 0 102 153))
        trans #(list (+ (* mag (first %)) base-x) ;; to fix to real xy-axis
                     (- reversed-y (+ (* mag (second %)) base-y)))
        points (zipmap (keys points) (map trans (vals points)))]

    (defn draw-arrow-head [xy1 xy2 top-mergin bot-mergin]
      (let [x1 (first xy1) x2 (first xy2)
            y1 (second xy1) y2 (second xy2)
            size (+ 25 (- bot-mergin))]
        (set-white)
        (q/push-matrix)
        (q/translate x1 y1)
        (q/rotate (+ (q/radians 270) (q/atan2 (- y2 y1) (- x2 x1))))
        (q/triangle 0 top-mergin 5 size -5 size)
        (q/pop-matrix)))

    (defn draw-point-with-name [name]
          (let [xy (name points) x (first xy) y (second xy)]
            (set-white)
            (q/ellipse x y (* circle-r 2) (* circle-r 2))
            (set-blue)
            (q/text (drop-colon name) (- x 5) (+ y 5))))

    (fn []
      ;; points & lines
      (q/background 255) ;; white background
      (q/stroke-weight 1)
      ;; draw lines
      (doall (map #(q/line (%1 points) (%2 points)) route (rest route)))
      (doall (map #(draw-arrow-head (%2 points) (%1 points) circle-r 0)
                  route (rest route)))
      ;; draw points with name
      (set-blue)
      ;; if this font is not in the environment, this code is ignored
      (q/text-font (q/create-font "DejaVu Sans Mono Bold" 16 true))
      (doall (map draw-point-with-name (keys points)))

      ;; XY-axis
      (q/stroke-weight 2)
      (let [x0 base-x, y0 (- reversed-y base-y)
            mergin 20, font-size 20, length 300
            x-line [(- x0 mergin) y0 (+ x0 length) y0]
            y-line [x0 (+ y0 mergin) x0 (- y0 length)]]
        (apply q/line x-line)
        (apply q/line y-line)
        (draw-arrow-head (drop 2 x-line) (take 2 x-line) 0 10)
        (draw-arrow-head (drop 2 y-line) (take 2 y-line) 0 10)
        (set-blue)
        (q/text-size font-size)
        (q/text "O" (+ 20 x0) (+ 20 y0))
        (q/text "X" (+ 5 (x-line 2)) (+ (x-line 3) 7)) ;; suitably
        (q/text "Y" (- (y-line 2) 5) (- (y-line 3) 5)) ;;
        ))))

(defn plot-route []
  (q/defsketch skt1
    :title "routes"
    :setup (fn [] (q/frame-rate 30) (q/smooth)) ;; anti-aliased
    :draw (draw-route sample-points route)
    :size [400 400]))

;; do (plot-graph) in repl