Difference between revisions of "Fractal Polygons"

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 +
In the last line of the input window there is the command
 +
<source lang="javascript">
 +
fracPolygone(5,100,0.4,5,1);
 +
</source>
 +
The meaning of the parameters is
 +
* 5: number of vertices of the regular polygone,
 +
* 100: length of a side of the initial poylgone,
 +
* 0.4: shrink factor from one level to the next,
 +
* 5: number of recursion steps
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* 1
 +
 
<html>
 
<html>
 
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
 
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
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<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxturtle.js"></script>
 
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxturtle.js"></script>
 
<form><textarea id="inputtext" rows=3 cols=35 wrap="off" style="width:600px;">
 
<form><textarea id="inputtext" rows=3 cols=35 wrap="off" style="width:600px;">
function fracPolygone(corner,len,shrink,recurs,start) {
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function fracPolygone(corner,len,shrink,recurs) {
 
     if (recurs>0) {
 
     if (recurs>0) {
         if (start==1) {
+
         if (argument.length==4) { // initial call
            start = 0;
 
 
             t.rt(180);
 
             t.rt(180);
             fracPolygone(corner,len*shrink,shrink,recurs-1,start);
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             fracPolygone(corner,len*shrink,shrink,recurs-1,1);
 
             t.lt(180);
 
             t.lt(180);
 
         }
 
         }
Line 17: Line 27:
 
         for(var i=0;i<corner-1;i++) {
 
         for(var i=0;i<corner-1;i++) {
 
             t.rt(180);
 
             t.rt(180);
             fracPolygone(corner,len*shrink,shrink,recurs-1,start);
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             fracPolygone(corner,len*shrink,shrink,recurs-1,1);
 
             t.lt(180);
 
             t.lt(180);
 
             t.fd(len);
 
             t.fd(len);
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t.setPos(-100,0);
 
t.setPos(-100,0);
 
t.setPenColor('blue');
 
t.setPenColor('blue');
fracPolygone(5,100,0.4,7,1);
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fracPolygone(5,100,0.4,5);
 
</textarea><br />
 
</textarea><br />
 
<input type="button" value="run" onClick="run()">
 
<input type="button" value="run" onClick="run()">

Revision as of 13:16, 21 December 2008

In the last line of the input window there is the command

fracPolygone(5,100,0.4,5,1);

The meaning of the parameters is

  • 5: number of vertices of the regular polygone,
  • 100: length of a side of the initial poylgone,
  • 0.4: shrink factor from one level to the next,
  • 5: number of recursion steps
  • 1


References

  • Peter Baptist, Wolfgang Neidhardt, Alfred Wassermann: Symmetry and Regular Polygons, Prispevki k poucevanju Matematike, The Improvement of Mathematics Education in Secondary Schools: A Tempus Project, Maribor 1996