1 #// Usage: jjs -fx -scripting logisticmap.js -- <initial_x> <R>
   2 
   3 /*
   4  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  *   - Redistributions of source code must retain the above copyright
  11  *     notice, this list of conditions and the following disclaimer.
  12  *
  13  *   - Redistributions in binary form must reproduce the above copyright
  14  *     notice, this list of conditions and the following disclaimer in the
  15  *     documentation and/or other materials provided with the distribution.
  16  *
  17  *   - Neither the name of Oracle nor the names of its
  18  *     contributors may be used to endorse or promote products derived
  19  *     from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  22  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  28  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  29  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 
  34 // Logistic map viewer using Java8 Streams and JavaFX
  35 // See also http://en.wikipedia.org/wiki/Logistic_map
  36 
  37 if (!$OPTIONS._fx || arguments.length < 2) {
  38     print("Usage: jjs -fx -scripting logisticmap.js -- <initial_x> <R>");
  39     exit(1);
  40 }
  41 
  42 // parameters for the logistic map
  43 var x = parseFloat(arguments[0]);
  44 var R = parseFloat(arguments[1]);
  45 var NUM_POINTS = arguments.length > 2? parseFloat(arguments[2]) : 20;
  46 
  47 // Java classes used
  48 var DoubleStream = Java.type('java.util.stream.DoubleStream');
  49 var LineChart = Java.type("javafx.scene.chart.LineChart");
  50 var NumberAxis = Java.type("javafx.scene.chart.NumberAxis");
  51 var Scene = Java.type("javafx.scene.Scene");
  52 var Stage = Java.type("javafx.stage.Stage");
  53 var XYChart = Java.type("javafx.scene.chart.XYChart");
  54 
  55 function start(stage) {
  56     stage.title = "Logistic Map: initial x = ${x}, R = ${R}";
  57     // make chart
  58     var xAxis = new NumberAxis();
  59     var yAxis = new NumberAxis();
  60     var lineChart = new LineChart(xAxis, yAxis);
  61     xAxis.setLabel("iteration");
  62     yAxis.setLabel("x");
  63     // make chart data series
  64     var series = new XYChart.Series();
  65     var data = series.data;
  66     // populate data using logistic iteration
  67     var i = 0;
  68     DoubleStream
  69         .generate(function() x = R*x*(1-x))
  70         .limit(NUM_POINTS)
  71         .forEach(
  72             function(value) {
  73                 data.add(new XYChart.Data(i, value));
  74                 i++;
  75             }
  76          );
  77     // add to stage
  78     var scene = new Scene(lineChart, 800, 600);
  79     lineChart.data.add(series);
  80     stage.scene = scene;
  81     stage.show();
  82 }