Sparklines

spars.clj

(ns sparks.core)

(def ticks '[▁ ▂ ▃ ▄ ▅ ▆ ▇ █])

(defn scale [smallest biggest x]
  (inc
    (/
     (* (dec (count ticks)) (- x smallest))
     (max (- biggest smallest) 1))))

(defn scaled-seqence [xs]
  (let [smallest (apply min xs)
        biggest (apply max xs)]
    (map (comp int (partial scale smallest biggest)) xs)))

(defn spark [xs]
  (map (comp ticks dec) (scaled-seqence xs)))