Bezier curves: Difference between revisions
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    p.push(brd.createElement('point',[Math.random()*8-4,Math.random()*8-4],  |     p.push(brd.createElement('point',[Math.random()*8-4,Math.random()*8-4],  | ||
            {strokeColor:col,fillColor:col}));     // data point  |             {strokeColor:col,fillColor:col}));     // data point  | ||
   brd.unsuspendUpdate();  | |||
};  | |||
var removeSegment = function() {  | |||
   brd.suspendUpdate();  | |||
   if (p.length>4) {  | |||
       p.splice(p.length-3,3);  | |||
   }  | |||
    brd.unsuspendUpdate();  |     brd.unsuspendUpdate();  | ||
};  | };  | ||
Revision as of 06:52, 29 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});