Function sign

src/plots/smith/helpers.js:3–8

(x)

'use strict';

function sign(x) {
    return (
        x < 0 ? -1 :
        x > 0 ? 1 : 0
    );
}

// adapted from Mike Bostock's https://observablehq.com/@mbostock/smith-chart
function smith(a) {