Difference between revisions of "Multiple logarithmic spirals"

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Eight logarithmic spirals defined by
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:<math>r = ae^{b\theta + k\cdot\pi/4 + \tau}\,.</math>
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<jsxgraph width="600" height="600" box="box1">
 
<jsxgraph width="600" height="600" box="box1">
  board = JXG.JSXGraph.initBoard('box1', {originX: 300, originY: 300, unitX: 25, unitY: 25});
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  board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-12, 12, 12, -12]});
  var a = board.createElement('slider', [[1,-1],[5,-1],[0,0.3,1]], {name:'a'});
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board.suspendUpdate();
  var b = board.createElement('slider', [[1,-2],[5,-2],[0,0.15,1]], {name:'b'});
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  var a = board.create('slider', [[1,-1],[5,-1],[0,0.3,1]], {name:'a'});
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  var b = board.create('slider', [[1,-2],[5,-2],[0,0.7,1]], {name:'b'});
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var tau = board.create('slider', [[-5,-3],[5,-3],[0,0,0.5]], {name:'&tau;'});
 
  for (var i=0;i<8;i++) {
 
  for (var i=0;i<8;i++) {
   (function(x) { return board.createElement('curve', [function(phi){return a.Value()*board.pow(Math.E,b.Value()*phi+Math.PI*x*0.25); }, [0, 0], 0, 8*Math.PI],
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   (function(x) { return board.create('curve', [function(phi){return a.Value()*Math.exp(b.Value()*(phi+Math.PI*x*0.25+tau.Value()*Math.PI)); }, [0, 0], -4*Math.PI, 8*Math.PI],
             {curveType:'polar', strokewidth:4});         
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             {curveType:'polar', strokewidth:1});         
 
   })(i);
 
   })(i);
 
  }
 
  }
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board.unsuspendUpdate();
 
</jsxgraph>
 
</jsxgraph>
  
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<source lang="javascript">
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board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-12, 12, 12, -12]});
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var a = board.create('slider', [[1,-1],[5,-1],[0,0.3,1]], {name:'a'});
 +
var b = board.create('slider', [[1,-2],[5,-2],[0,0.7,1]], {name:'b'});
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var tau = board.create('slider', [[-5,-3],[5,-3],[0,0,2]], {name:'&tau;'});
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for (var i=0;i<8;i++) {
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  (function(x) { return board.create('curve', [function(phi){return a.Value()*Math.exp(b.Value()*(phi+Math.PI*x*0.25+tau.Value()*Math.PI)); }, [0, 0], -4*Math.PI, 8*Math.PI],
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            {curveType:'polar', strokewidth:1});       
 +
  })(i);
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}
 +
</source>
  
 
[[Category:Examples]]
 
[[Category:Examples]]
 
[[Category:Curves]]
 
[[Category:Curves]]

Latest revision as of 11:49, 8 June 2011

Eight logarithmic spirals defined by

[math]r = ae^{b\theta + k\cdot\pi/4 + \tau}\,.[/math]

 board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-12, 12, 12, -12]});
 var a = board.create('slider', [[1,-1],[5,-1],[0,0.3,1]], {name:'a'});
 var b = board.create('slider', [[1,-2],[5,-2],[0,0.7,1]], {name:'b'});
 var tau = board.create('slider', [[-5,-3],[5,-3],[0,0,2]], {name:'&tau;'});
 for (var i=0;i<8;i++) {
   (function(x) { return board.create('curve', [function(phi){return a.Value()*Math.exp(b.Value()*(phi+Math.PI*x*0.25+tau.Value()*Math.PI)); }, [0, 0], -4*Math.PI, 8*Math.PI],
             {curveType:'polar', strokewidth:1});        
   })(i);
 }