             chart && next();

                function next() {
                    var nextInterval = rotate % 90 === 0 ? 2000: 70;
                    rotate = (rotate + 1) % 90;
                    setTimeout(function () {
                        chart.setOption({
                            xAxis: {
                                id: 'xx',
                                axisLabel: {
                                    rotate: rotate
                                }
                            },
   