Function vMag

libs/echarts/echarts.simple.js:15185–15187

(v)

var PI = Math.PI;

var vMag = function (v) {
    return Math.sqrt(v[0] * v[0] + v[1] * v[1]);
};
var vRatio = function (u, v) {
    return (u[0] * v[0] + u[1] * v[1]) / (vMag(u) * vMag(v));
};