Cubic spline interpolation
From JSXGraph Wiki
Under Construction -- NOT YET WORKING
Constructs a cubic spline through given points. Points can be added by clicking on "Add point".
References
The underlying JavaScript code
function addPoint() {
p.push(board.createElement('point',[(Math.random()-0.5)*10,(Math.random()-0.5)*3],{style:6}));
board.update();
}