Difference between revisions of "Random walks"

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Line 18: Line 18:
 
<option value="100">100</option>
 
<option value="100">100</option>
 
<option value="200">200</option>
 
<option value="200">200</option>
</select> where <math>stepsize=5</math><br />
+
</select> where <math>stepsize=5</math> and <i>Number of steps per walk = 1000</i><br />
 
<input type="button" value="run" onClick="run()">
 
<input type="button" value="run" onClick="run()">
 
<input type="button" value="clear" onClick="clearturtle()">
 
<input type="button" value="clear" onClick="clearturtle()">
Line 76: Line 76:
 
   for (i=0;i<nr;i++) {
 
   for (i=0;i<nr;i++) {
 
     t.setPenColor(HSV2RGB(Math.round(Math.random()*255),Math.random(),Math.random()));
 
     t.setPenColor(HSV2RGB(Math.round(Math.random()*255),Math.random(),Math.random()));
     for (j=0;j<100;j++) {
+
     for (j=0;j<200;j++) {
 
         var a = Math.floor(360*Math.random());  
 
         var a = Math.floor(360*Math.random());  
 
         t.right(a);  
 
         t.right(a);  

Revision as of 08:30, 27 May 2009

Number of random walks: where stepsize=5 and Number of steps per walk = 1000

Average square of the distance between starting point and endpoint of the walks:

Source code

<jsxgraph width="600" height="600">
var brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 300, unitX: 3, unitY: 3});
var t = brd.createElement('turtle');

function run() {
  var i,j,dist,sumdist=0.0;
  var stepSize = 5; 
  brd.suspendUpdate();
  var nr = $('number').value*1;
  for (i=0;i<nr;i++) {
     for (j=0;j<100;j++) {
        var a = Math.floor(360*Math.random()); 
        t.right(a); 
        t.forward(stepSize);
     }
     dist = t.pos[0]*t.pos[0]+t.pos[1]*t.pos[1];
     sumdist += dist;
     t.home();
  }
  $('output').value = (sumdist/nr).toFixed(3);
  brd.unsuspendUpdate();
}
function clearturtle() {
  sumist = 0.0
  t.cs();
}
</jsxgraph>

External links