nashorn/samples/logisticmap.js
changeset 24283 bda887c0088a
child 26067 b32ccc3a76c9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/samples/logisticmap.js	Wed May 07 20:20:58 2014 +0530
@@ -0,0 +1,82 @@
+#// Usage: jjs -fx -scripting logisticmap.js -- <initial_x> <R>
+
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Logistic map viewer using Java8 Streams and JavaFX
+// See also http://en.wikipedia.org/wiki/Logistic_map
+
+if (!$OPTIONS._fx || arguments.length < 2) {
+    print("Usage: jjs -fx -scripting logisticmap.js -- <initial_x> <R>");
+    exit(1);
+}
+
+// parameters for the logistic map
+var x = parseFloat(arguments[0]);
+var R = parseFloat(arguments[1]);
+var NUM_POINTS = arguments.length > 2? parseFloat(arguments[2]) : 20;
+
+// Java classes used
+var DoubleStream = Java.type('java.util.stream.DoubleStream');
+var LineChart = Java.type("javafx.scene.chart.LineChart");
+var NumberAxis = Java.type("javafx.scene.chart.NumberAxis");
+var Scene = Java.type("javafx.scene.Scene");
+var Stage = Java.type("javafx.stage.Stage");
+var XYChart = Java.type("javafx.scene.chart.XYChart");
+
+function start(stage) {
+    stage.title = "Logistic Map: initial x = ${x}, R = ${R}";
+    // make chart
+    var xAxis = new NumberAxis();
+    var yAxis = new NumberAxis();
+    var lineChart = new LineChart(xAxis, yAxis);
+    xAxis.setLabel("iteration");
+    yAxis.setLabel("x");
+    // make chart data series
+    var series = new XYChart.Series();
+    var data = series.data;
+    // populate data using logistic iteration
+    var i = 0;
+    DoubleStream
+        .generate(function() x = R*x*(1-x))
+        .limit(NUM_POINTS)
+        .forEach(
+            function(value) {
+                data.add(new XYChart.Data(i, value));
+                i++;
+            }
+         );
+    // add to stage
+    var scene = new Scene(lineChart, 800, 600);
+    lineChart.data.add(series);
+    stage.scene = scene;
+    stage.show();
+}