Function force

docs/app/js/sanddance-app.js:135730–135734

()

    if (x == null) x = 0;
    if (y == null) y = 0;
    function force() {
        var i, n = nodes.length, node, sx = 0, sy = 0;
        for(i = 0; i < n; ++i)node = nodes[i], sx += node.x, sy += node.y;
        for(sx = (sx / n - x) * strength, sy = (sy / n - y) * strength, i = 0; i < n; ++i)node = nodes[i], node.x -= sx, node.y -= sy;
    }
    force.initialize = function(_) {
        nodes = _;
    };