Function quartiles

docs/app/js/sanddance-app.js:119114–119120

(array, f)

    return p.map((_)=>(0, _d3Array.quantileSorted)(values, _));
}
function quartiles(array, f) {
    return quantiles(array, [
        0.25,
        0.50,
        0.75
    ], f);
}
// Theory, Practice, and Visualization. Wiley.
function estimateBandwidth(array, f) {
    const n = array.length, d = (0, _d3Array.deviation)(array, f), q = quartiles(array, f), h = (q[2] - q[0]) / 1.34, v = Math.min(d, h) || d || Math.abs(q[0]) || 1;