Polynomial regression II

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Revision as of 14:11, 29 September 2010 by A WASSERMANN (talk | contribs)
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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

<jsxgraph width="700" height="500">
brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2, 100, 220, -70], grid: false, axis:true});
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:" "})); 

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();}