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.
###install
npm install cubic-spline###usage
var spline = require('cubic-spline');
var xs = [1,2,3,4,5];
var ys = [9,3,6,2,4];
// get Y at arbitrary X
console.log(spline(1.4, xs, ys));
// interpolate a line at a higher resolution
for(var i = 0; i < 50; i++) {
console.log(spline(i*.1, xs, ys));
}###test
npm test