Analemma is a Clojure-based SVG DSL and charting library. In astronomy, an analemma is the figure drawn in the sky by the different positions of the Sun recorded at the same time and location during the course of a year.

Example Charts

Plotting Analemma Data

(spit "analemma.svg"
      (emit-svg
        (-> (xy-plot :xmin -30 :maxx 10,
                     :ymin -30 :maxy 30
                     :height 500 :width 500)
	     (add-points analemma-data))))

Plotting Sine and Cosine

(spit "sin-cos.svg"
      (emit-svg
        (let [x (range -5 5 0.05)
              y1 (map #(Math/cos %) x)
              y2 (map #(Math/sin %) x)]
          (-> (xy-plot :minx -5 :xmax 5 :ymin -1.5 :maxy 1.5)
              (add-points [x y1] :transpose-data?? true)
              (add-points [x y2] :transpose-data?? true
                          :color (rgb 255 0 0))))))

Creating the Analemma logo

(emit
  (svg
    (apply group
           (rect 0 0 160 500 :fill "#ffffff")
           (-> (text {:x 120 :y 60} "Analemma")
               (style :fill #"000066"
                      :font-family "Garamond"
                      :font-size "75px"
                      :alignment-baseline :middle))
           (for [[x y] analemma-data]
             (circle (translate-value x -30 5 0 125)
                     (translate-value y -25 30 125 0)
                     2 :fill "#000066")))))

See the Analemma website for more examples.

Copyright © 2011 David Edgar Liebke

Distributed under the Eclipse Public License, the same as Clojure.