interpolateJS
Lagrange interpolation to the rescue!
Intro
InterpolateJS constructs a linear interpolation function p(x)
for your provided set of x and y-values, using the Lagrange basis polynomials.
Using .evaluate()
you can then provide an x-value to the function, and get an interpolated y-value.
Getting started
Installation:
npm i --save @theiliad/interpolatejs
Usage
import/require:
import { interpolation, fraction } from "@theiliad/interpolatejs/index";
const xValues = [fraction(1, 3), fraction(1, 4), 1];
const yValues = [2, -1, 7];
const pOfx = interpolation(xValues, yValues);
console.log("p(1/3) =", pOfx.evaluate(fraction(1, 3)));
// ==> p(1/3) = 2
In-browser CDN Usage:
<script src="https://unpkg.com/@theiliad/interpolatejs"></script>
<script>
const { interpolation, fraction } = interpolateJS;
const xValues = [fraction(1, 3), fraction(1, 4), 1];
const yValues = [2, -1, 7];
const pOfx = interpolation(xValues, yValues);
console.log(
"p(1/3) =",
pOfx.evaluate(
fraction(1, 3)
)
);
</script>