Similarity Coefficients in JS

SimilarityMeasureBinary.js

// Quickly wrote this to save me time in class instead of calculating all of this stuff
/**
var d1 = [0.8, 0.7, 0.9, 0, 0, 0.2];
var d2 = [0.4, 0.3, 0.5, 0, 0, 0];
var d3 = [0.9, 0, 0.8, 0.5, 0, 0];
var d4 = [0.2, 0, 0, 0.8, 0, 0.9];
var d5 = [0.7, 0.9, 0.7, 0.4, 0, 0];
var d6 = [0.3, 0.6, 0.7, 0.7, 0, 0];

similarity(d1, d2, "dice"); // 0.8571428571428571
similarity(d1, d2, "jaccard"); // 0.75
similarity(d1, d2, "cosine"); // 0.8660254037844387
similarity(d1, d2, "overlap"); // 1
**/

/**
 * Calculate the similarity measure of two documents within a matrix
 * @param  {array} d1                 order dependent list of document 1 and term values
 * @param  {array} d2                 order dependent list of document 2 and term values
 * @param  {string} coefficientMeasure the coefficient measure: jaccard, dice, cosine, or overlap
 * @return {int}                    the coefficient measure of desired equation
 */
function similarity(d1, d2, coefficientMeasure) {
    var AND = [],
        OR = [],
        d1List = [],
        d2List = [];

    for (var i = 0; i < d1.length; i++) {
        if (d1[i] > 0 & d2[i] > 0) {
            AND.push(i);
        }
        if (d1[i] > 0 || d2[i] > 0) {
            OR.push(i);
        }
        if (d1[i] > 0) {
            d1List.push(i);
        }
        if (d2[i] > 0) {
            d2List.push(i);
        }
    }

    var n, d;
    var coefficient = coefficientMeasure.toLowerCase();

    switch (coefficient) {
        case "jaccard":
            n = AND.length;
            d = OR.length;
            break;

        case "dice":
            n = 2 * AND.length;
            d = d1List.length + d2List.length;
            break;

        case "cosine":
            n = AND.length;
            d = (Math.sqrt(d1List.length) * Math.sqrt(d2List.length))
            break;

        case "overlap":
            n = AND.length;
            d = Math.min(d1List.length, d2List.length);
            break;
    }

    return n/d;
};