Difference between revisions of "Bezier curves"

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The red points are connected by a cubic Bezier curve. The blue points are the control points.
 
<jsxgraph width="600" height="600">
 
<jsxgraph width="600" height="600">
 
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-4,4,4,-4],keepaspectratio:true,axis:true});
 
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-4,4,4,-4],keepaspectratio:true,axis:true});
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p.push(brd.createElement('point',[2,-0.5],{strokeColor:col,fillColor:col}));      // data point
 
p.push(brd.createElement('point',[2,-0.5],{strokeColor:col,fillColor:col}));      // data point
  
var c = brd.createElement('curve', JXG.Math.Numerics.bezier(p),{strokecolor:'blue', strokeOpacity:0.8, strokeWidth:3});  
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var c = brd.createElement('curve', JXG.Math.Numerics.bezier(p),{strokecolor:'blue', strokeOpacity:0.6, strokeWidth:5});
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</jsxgraph>
 +
 
 +
===The underlying JavaScript code===
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<source lang="javvascript">
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var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-4,4,4,-4],keepaspectratio:true,axis:true});
 +
 
 +
var p = [];
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 +
col = 'red';
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p.push(brd.createElement('point',[2,1],{strokeColor:col,fillColor:col}));        // data point
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col = 'blue';
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p.push(brd.createElement('point',[0.75,2.5],{strokeColor:col,fillColor:col})); // control point
 +
p.push(brd.createElement('point',[-0.3,0.3],{strokeColor:col,fillColor:col}));  // control point
 +
 
 +
col = 'red';
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p.push(brd.createElement('point',[-3,1],{strokeColor:col,fillColor:col}));      // data point
 +
col = 'blue';
 +
p.push(brd.createElement('point',[-0.75,-2.5],{strokeColor:col,fillColor:col})); // control point
 +
p.push(brd.createElement('point',[1.5,-2.8],{strokeColor:col,fillColor:col}));     // control point
  
</jsxgraph>
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col = 'red';
 +
p.push(brd.createElement('point',[2,-0.5],{strokeColor:col,fillColor:col}));      // data point
 +
 
 +
var c = brd.createElement('curve', JXG.Math.Numerics.bezier(p),{strokecolor:'blue', strokeOpacity:0.6, strokeWidth:5});
 +
</source>
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[[Category:Examples]]
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[[Category:Curves]]

Revision as of 10:55, 28 September 2009

The red points are connected by a cubic Bezier curve. The blue points are the control points.

The underlying JavaScript code

var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-4,4,4,-4],keepaspectratio:true,axis:true});

var p = [];

col = 'red'; 
p.push(brd.createElement('point',[2,1],{strokeColor:col,fillColor:col}));        // data point
col = 'blue'; 
p.push(brd.createElement('point',[0.75,2.5],{strokeColor:col,fillColor:col})); // control point
p.push(brd.createElement('point',[-0.3,0.3],{strokeColor:col,fillColor:col}));   // control point

col = 'red'; 
p.push(brd.createElement('point',[-3,1],{strokeColor:col,fillColor:col}));       // data point
col = 'blue'; 
p.push(brd.createElement('point',[-0.75,-2.5],{strokeColor:col,fillColor:col})); // control point
p.push(brd.createElement('point',[1.5,-2.8],{strokeColor:col,fillColor:col}));     // control point

col = 'red'; 
p.push(brd.createElement('point',[2,-0.5],{strokeColor:col,fillColor:col}));      // data point

var c = brd.createElement('curve', JXG.Math.Numerics.bezier(p),{strokecolor:'blue', strokeOpacity:0.6, strokeWidth:5});