Difference between revisions of "Polynomial regression II"

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Here are 30 randomly distributed points. The range of these points can be adjusted by the slider 'scale'.
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Through these points a regression polynomial is computed. The degree of this polynomial can be adjusted by the slider 'degree'.
 +
 
<jsxgraph width="700" height="500">
 
<jsxgraph width="700" height="500">
 
brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2, 100, 220, -70], grid: false, axis:true});
 
brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2, 100, 220, -70], grid: false, axis:true});
 
brd.suspendUpdate();
 
brd.suspendUpdate();
deg = brd.createElement('slider',[[10,90],[100,90],[1,1,10]],{name:'degree',snapWidth:1});     
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deg = brd.create('slider',[[10,90],[100,90],[1,1,10]],{name:'degree',snapWidth:1});   
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s = brd.create('slider',[[10,70],[100,70],[0,1,3]],{name:'scale'});     
 
pointlist = [];
 
pointlist = [];
 
for (i=0; i<30;i++) {
 
for (i=0; i<30;i++) {
     pointlist.push(brd.createElement('point', [function() { return 200*Math.random(); }, function() { return 30*Math.random()+20;}], { style:4, strokecolor:"#0000a0", name:" "}));  
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     pointlist.push(brd.create('point', [function() { return 200*Math.random(); }, function() { return s.Value()*30*Math.random()+20;}], { style:4, strokecolor:"#0000a0", name:" "}));  
 
}
 
}
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brd.unsuspendUpdate();
  
 
regression = JXG.Math.Numerics.regressionPolynomial(deg,pointlist);  
 
regression = JXG.Math.Numerics.regressionPolynomial(deg,pointlist);  
reg = brd.createElement('functiongraph',[regression],{strokeColor:'green'});     
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reg = brd.create('functiongraph',[regression],{strokeColor:'green'});     
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t = brd.create('text',[20,-40,
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            function(){ return "r(x) = " + regression.getTerm();}
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            ],
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            {strokeColor:'black',fontSize:'14px'});   
 +
 
 +
</jsxgraph>
 +
 
 +
===The underlying JavaScript code===
 +
<source lang="javascript">
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brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2, 100, 220, -70], grid: false, axis:true});
 +
brd.suspendUpdate();
 +
deg = brd.create('slider',[[10,90],[100,90],[1,1,10]],{name:'degree',snapWidth:1});   
 +
s = brd.create('slider',[[10,70],[100,70],[0,1,3]],{name:'scale'});   
 +
pointlist = [];
 +
for (i=0; i<30;i++) {
 +
    pointlist.push(brd.create('point', [function() { return 200*Math.random(); }, function() { return s.Value()*30*Math.random()+20;}], { style:4, strokecolor:"#0000a0", name:" "}));
 +
}
 
brd.unsuspendUpdate();
 
brd.unsuspendUpdate();
  
 +
regression = JXG.Math.Numerics.regressionPolynomial(deg,pointlist);
 +
reg = brd.create('functiongraph',[regression],{strokeColor:'green'});   
 +
t = brd.create('text',[20,-40,
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            function(){ return "r(x) = " + regression.getTerm();}
 +
            ],
 +
            {strokeColor:'black',fontSize:'14px'});   
 +
</source>
  
</jsxgraph>
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[[Category:Examples]]

Latest revision as of 12:48, 8 June 2011

Here are 30 randomly distributed points. The range of these points can be adjusted by the slider 'scale'. Through these points a regression polynomial is computed. The degree of this polynomial can be adjusted by the slider 'degree'.

The underlying JavaScript code

brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2, 100, 220, -70], grid: false, axis:true});
brd.suspendUpdate();
deg = brd.create('slider',[[10,90],[100,90],[1,1,10]],{name:'degree',snapWidth:1});     
s = brd.create('slider',[[10,70],[100,70],[0,1,3]],{name:'scale'});     
pointlist = [];
for (i=0; i<30;i++) {
    pointlist.push(brd.create('point', [function() { return 200*Math.random(); }, function() { return s.Value()*30*Math.random()+20;}], { style:4, strokecolor:"#0000a0", name:" "})); 
}
brd.unsuspendUpdate();

regression = JXG.Math.Numerics.regressionPolynomial(deg,pointlist); 
reg = brd.create('functiongraph',[regression],{strokeColor:'green'});     
t = brd.create('text',[20,-40,
            function(){ return "r(x) = " + regression.getTerm();}
            ],
            {strokeColor:'black',fontSize:'14px'});