Function convexPolygonArea

test/jasmine/tests/funnelarea_test.js:24–38

(points)

var LEGEND_ENTRIES_SELECTOR = '.legendpoints path';

function convexPolygonArea(points) {
    var s1 = 0;
    var s2 = 0;
    var n = points.length;
    for(var i = 0; i < n; i++) {
        var k = (i + 1) % n;
        var x0 = points[i][0];
        var y0 = points[i][1];
        var x1 = points[k][0];
        var y1 = points[k][1];
        s1 += x0 * y1;
        s2 += x1 * y0;
    }
    return 0.5 * Math.abs(s1 - s2);
}

describe('Funnelarea defaults', function() {
    function _supply(trace, layout) {