Comparison of gnuplot, Incanter, oz/vega-lite for plotting usage data - Incanter

incanter.clj

(ns clj-charting.incanter
  (:require
    [incanter.core :refer :all]
    [incanter.charts :refer :all]
    [clj-charting.usage-chart-preparation :refer [read-usage-data moving-window-means]])
  (:import
    [org.jfree.chart JFreeChart]
    [org.jfree.chart.plot XYPlot]
    (org.jfree.chart.axis ValueAxis NumberAxis NumberTickUnit TickUnitSource TickUnit)
    (java.text NumberFormat DecimalFormat FieldPosition)))

(defn merge-y-axis
  "Merge the Y axis of two line / time series charts. The former chart will have
  the left Y axis, and the latter will have the right. Incanter does not support 2 Y
  axes out of the box.
  Source: https://matthewdowney.github.io/clojure-incanter-plot-multiple-y-axis.html"
  [^JFreeChart chart ^JFreeChart chart-to-merge]
  (let [^XYPlot plot (.getPlot chart-to-merge)]
    (doto ^XYPlot (.getPlot chart)
      (.setRangeAxis 1 (.getRangeAxis plot))
      (.setDataset 1 (.getDataset plot))
      (.mapDatasetToRangeAxis 1 1)
      (.setRenderer 1 (.getRenderer plot)))
    (-> (.getPlot chart)
        (.getLegendItems)
        (.addAll (.getLegendItems plot)))
    chart))

(defn byte-scale 
  "For the given number [in bytes] return [scale, scale suffix] so that we can divide it 
   by the scale and display with the corresponding suffix.
   Example: 2333 -> [1024 \"kB\"]"
  [num]
  (let [k 1024
        m (int (Math/pow 1024 2))
        g (int (Math/pow 1024 3))]
    (condp <= num
      g [g "GB"]
      m [m "MB"]
      k [k "kB"]
      [1 ""])))

(defn format-bytes 
  "For the given number [in bytes] return [the number scaled down, the scale suffix such as \"kB\"].
   Example: 2333 -> [2.278 \"kB\"]"
  [num]
  (let [[scale unit] (byte-scale num)]
    [(/ num scale) unit]))

;; Instance of NumberFormat that displays a byte number scaled down and with the scale suffix
;; Example: 2333 -> \"2.3kB\"]"
(def byteFmt (let [dec-fmt (java.text.DecimalFormat. "#.#")]
               (proxy [java.text.NumberFormat] []
                 (format [^double number, ^StringBuffer toAppendTo, ^FieldPosition pos]
                   (let [[n u] (format-bytes number)]
                     (.append
                       (.format dec-fmt n toAppendTo pos)
                       u))))))

(defn nearest-byte-tick
  "For the given byte number, find out what tick to show on the axis; 
   e.g. we would rather see a tick such as '800MB' than '783.5MB' on it."
  ([^double size tick-fn]
   (let [[scale] (byte-scale size)]
     (NumberTickUnit.
       (* scale
          ;; FIXME if size = 1000 upgrade to 1024
          (.getSize
            (tick-fn
              (NumberTickUnit. (/ size scale)))))
       byteFmt))))

(def byte-tick-source
  "TickUnitSource suitable for byte values spanning multiple of kB - MB - GB"
  ;; TODO Instead of reusing IntegerTickUnits, reimplement it to support powers of 2
  (let [int-tick-units (NumberAxis/createIntegerTickUnits)]
    (reify
      TickUnitSource
      (^TickUnit getLargerTickUnit [_ ^TickUnit unit]
        (nearest-byte-tick
          (.getSize unit)
          #(.getLargerTickUnit int-tick-units %)))
      (^TickUnit getCeilingTickUnit [me ^TickUnit unit]
        (.getCeilingTickUnit me (.getSize unit)))
      (^TickUnit getCeilingTickUnit [_ ^double size]
        (nearest-byte-tick
          size
          #(.getCeilingTickUnit int-tick-units %))))))

(defn set-bytes-tick-unit [^JFreeChart chart]
  (let [^XYPlot plot (.getPlot chart)
        ^NumberAxis axis (.getRangeAxis plot)]
    (.setStandardTickUnits axis byte-tick-source)
    chart))


(defn plot-usage [file]
  (let [data (read-usage-data file)
        time (sel data :cols 0)
        mem (sel data :cols 1)
        cpu (sel data :cols 2)]
    (->
      (time-series-plot time cpu :title file :y-label "cpu [%]"  :legend true)
      (add-lines time (moving-window-means 60 cpu) :series-label "cpu (mean)")
      (merge-y-axis
        (set-bytes-tick-unit
          (time-series-plot time mem :series-label "Memory")))
      (view))))

(plot-usage "siege-c10-all-urls-async-node11.dat")