Lagrange interpolation, show term

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Revision as of 06:57, 4 October 2022 by A WASSERMANN (talk | contribs)

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". The dotted line is the graph of the first derivative, the dashed line is the graph of the second derivative.

References

The underlying JavaScript code

var board = JXG.JSXGraph.initBoard('box', {boundingbox: [-5, 10, 7, -6], axis: true});

var points = [];
points[0] = board.create('point', [-1,2], {size:4});
points[1] = board.create('point', [3,-1], {size:4});
var f = JXG.Math.Numerics.lagrangePolynomial(points);
var graph = board.create('functiongraph', [f, -10, 10], {strokeWidth:3});
var d1 = board.create('functiongraph', [JXG.Math.Numerics.D(f), -10, 10], {dash:1});

function addPoint() {
    points.push(board.create('point',[(Math.random()-0.5)*10,(Math.random()-0.5)*3],{size:4}));
    board.update();
}

function removePoint() {
    if (points.length > 2) {
      board.removeObject(points[points.length - 1]);
      points.pop();
    }
    //board.update();
}

document.getElementById('add').addEventListener("click", addPoint, false);
document.getElementById('remove').addEventListener("click", removePoint, false);