Difference between revisions of "Polynomial regression II"

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===The underlying JavaScript code===
 
===The underlying JavaScript code===
<source lang="xml">
+
<source lang="javascript">
<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();
Line 41: Line 40:
 
             ],
 
             ],
 
             {strokeColor:'black',fontSize:'14px'});     
 
             {strokeColor:'black',fontSize:'14px'});     
</jsxgraph>
 
 
</source>
 
</source>
  
 
[[Category:Examples]]
 
[[Category:Examples]]

Latest revision as of 13:48, 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'});