Function lognormal

docs/app/js/sanddance-app.js:119494–119515

(mean, stdev)

    return Math.exp(quantileNormal(p, mean, stdev));
}
function lognormal(mean, stdev) {
    let mu, sigma;
    const dist = {
        mean (_) {
            if (arguments.length) {
                mu = _ || 0;
                return dist;
            } else return mu;
        },
        stdev (_) {
            if (arguments.length) {
                sigma = _ == null ? 1 : _;
                return dist;
            } else return sigma;
        },
        sample: ()=>sampleLogNormal(mu, sigma),
        pdf: (value)=>densityLogNormal(value, mu, sigma),
        cdf: (value)=>cumulativeLogNormal(value, mu, sigma),
        icdf: (p)=>quantileLogNormal(p, mu, sigma)
    };
    return dist.mean(mean).stdev(stdev);
}
function mixture(dists, weights) {
    let m = 0, w1;
    function normalize(x) {