给highcharts坐标设值有关问题

$(function () {

        var chart = new Highcharts.Chart({

            chart: {

                renderTo: 'container3',

                plotBorderWidth: 1,

                zoomx:true,

                type: 'line'

            },

            title: {

                text: null

            },

            credits:{

                enabled:false,

                position: {

                    align: 'left',

                    x: 350,

                    verticalAlign: 'bottom'

                }

            },

            legend: {

                enabled:true



            },



            xAxis: {

                type: 'datetime',

                min:minDate,  //0表示1月 以此类推

                max:maxDate,

                tickInterval :30*24*3600*1000,//X轴点间隔

                labels: {

                    align: 'left',

                    formatter: function() {

                        return Highcharts.dateFormat('%Y%m%d', this.value);

                    }

                }

            },

            yAxis:  [

                {