dojox
Version:
Dojo eXtensions, a rollup of many useful sub-projects and varying states of maturity – from very stable and robust, to alpha and experimental. See individual projects contain README files for details.
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HTML
<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" >
<head>
<title>Pi calculation</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
@import "../../../dojo/resources/dojo.css";
@import "../../../dijit/tests/css/dijitTests.css";
</style>
<script type="text/javascript" src="../../../dojo/dojo.js" data-dojo-config="isDebug: true"></script>
<script type="text/javascript">
dojo.require("dojox.gfx");
var iterations = 0, inCounter = 0, totalCounter = 0,
interval, surface;
var compute = function(){
var x = Math.random();
var y = Math.random();
var pointX = Math.round(x * 300);
var pointY = Math.round(y * 300);
var pointColor = "red";
if(x*x + y*y < 1){
inCounter++;
pointColor = "green";
}
surface.createCircle({cx: pointX, cy: pointY, r: 3}).
setFill(pointColor).setStroke({color: pointColor, width: 2});
totalCounter++;
if(totalCounter % 100 == 0 || totalCounter == iterations){
var PI = parseFloat(inCounter / totalCounter) * 4;
var error = (PI - Math.PI) / Math.PI * 100; // in %
dojo.byId("result").innerHTML = PI + " (error = " + error.toFixed(2) +
"%) after " + totalCounter + " points";
}
if(totalCounter == iterations){
clearInterval(interval);
dojo.byId("startButton").disabled = false;
}
};
var go = function(){
dojo.byId("startButton").disabled = true;
dojo.byId("result").innerHTML = " ";
inCounter = totalCounter = 0;
iterations = parseInt(0 + parseInt(dojo.byId("iterations").value), 10);
interval = setInterval(compute, 20);
};
var init = function(){
surface = dojox.gfx.createSurface("test", 300, 300);
dojo.connect(dojo.byId("startButton"), "onclick", this, go);
};
dojo.addOnLoad(init);
</script>
</head>
<body>
<h1>PI demo</h1>
<p>Visualization of calculating PI using the Monte Carlo method.</p>
<p>
<label>Iterations:</label> <input type="text" name="iterations" value="500" id="iterations"/>
<input type="button" name="start" value="start" id="startButton" />
</p>
<p><span style="color:green">Green</span>: x^2 + y^2 <= 1, <span style="color:red">Red</span>: x^2 + y^2 > 1</p>
<p>Estimated value for PI: <span id="result" style="font-weight: bold"></span></p>
<div id="test" style="width: 300px; height: 300px;border:1px solid black"></div>
<p>That's all Folks!</p>
</body>
</html>