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 }