docs: function() {
      this.compute('end');
      var vector = this.graph.getNode(this.root).pos.getc().scale(-1);
      Graph.Util.moebiusTransformation(this.graph, [ vector ], [ 'end' ],
          'end', "ignore");
      this.graph.eachNode(function(node) {
        if (node.ignore) {
          node.endPos.rho = node.pos.rho;
          node.endPos.theta = node.pos.theta;
        }
      });
    }