A slight modification of Ivan Kuckir's cubic spline implementation, cubic-spline guesses the value of y for any x value on a line. This is helpful for smoothing line graphs.
npm install cubic-splineconst Spline = require('cubic-spline');
const xs = [1, 2, 3, 4, 5];
const ys = [9, 3, 6, 2, 4];
// new a Spline object
const spline = new Spline(xs, ys);
// get Y at arbitrary X
console.log(spline.at(1.4));
// interpolate a line at a higher resolution
for (let i = 0; i < 50; i++) {
console.log(spline.at(i * 0.1));
}npm testnpm run lint