Lagrange interpolation (dup)

Constructs a polynomial of degree [math]\displaystyle{ n }[/math] through [math]\displaystyle{ n+1 }[/math] given points. Points can be added by clicking on "Add point".

References

• http://en.wikipedia.org/wiki/Lagrange_polynomial

The underlying JavaScript code

<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<div id="box" class="jxgbox" style="width:600px; height:400px;"></div>

var board = JXG.JSXGraph.initBoard('box', {originX: 250, originY: 250, unitX: 50, unitY: 25, axis:true});
var p = [];
p[0] = board.create('point', [-1,2], {style:6});
p[1] = board.create('point', [3,-1], {style:6});
p[2] = board.create('point', [-3,0], {style:6});
var graph = board.create('functiongraph', [board.lagrangePolynomial(p), -10, 10]);

function addPoint() {
      p.push(board.createElement('point',[(Math.random()-0.5)*10,(Math.random()-0.5)*3],{style:6}));
      board.update();
}