Difference between revisions of "Bezier curves"

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Line 8: Line 8:
 
p.push(brd.createElement('point',[2,1],{strokeColor:col,fillColor:col}));        // data point
 
p.push(brd.createElement('point',[2,1],{strokeColor:col,fillColor:col}));        // data point
 
col = 'blue';  
 
col = 'blue';  
p.push(brd.createElement('point',[0.75,2.5],{strokeColor:col,fillColor:col})); // control point
+
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
 
p.push(brd.createElement('point',[-0.3,0.3],{strokeColor:col,fillColor:col}));  // control point
  
Line 15: Line 15:
 
col = 'blue';  
 
col = 'blue';  
 
p.push(brd.createElement('point',[-0.75,-2.5],{strokeColor:col,fillColor:col})); // control point
 
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
+
p.push(brd.createElement('point',[1.5,-2.8],{strokeColor:col,fillColor:col}));   // control point
  
 
col = 'red';  
 
col = 'red';  
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:0.6, strokeWidth:5});  
+
var c = brd.createElement('curve', JXG.Math.Numerics.bezier(p), {strokecolor:'blue', strokeOpacity:0.6, strokeWidth:5});  
 
</jsxgraph>
 
</jsxgraph>
  
Line 32: Line 32:
 
p.push(brd.createElement('point',[2,1],{strokeColor:col,fillColor:col}));        // data point
 
p.push(brd.createElement('point',[2,1],{strokeColor:col,fillColor:col}));        // data point
 
col = 'blue';  
 
col = 'blue';  
p.push(brd.createElement('point',[0.75,2.5],{strokeColor:col,fillColor:col})); // control point
+
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
 
p.push(brd.createElement('point',[-0.3,0.3],{strokeColor:col,fillColor:col}));  // control point
  
Line 39: Line 39:
 
col = 'blue';  
 
col = 'blue';  
 
p.push(brd.createElement('point',[-0.75,-2.5],{strokeColor:col,fillColor:col})); // control point
 
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
+
p.push(brd.createElement('point',[1.5,-2.8],{strokeColor:col,fillColor:col}));   // control point
  
 
col = 'red';  
 
col = 'red';  
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:0.6, strokeWidth:5});  
+
var c = brd.createElement('curve', JXG.Math.Numerics.bezier(p), {strokecolor:'blue', strokeOpacity:0.6, strokeWidth:5});  
 
</source>
 
</source>
  
 
[[Category:Examples]]
 
[[Category:Examples]]
 
[[Category:Curves]]
 
[[Category:Curves]]

Revision as of 10:56, 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});