highcharts（数据可视化框架），ajax传递数据问题

<%--highcharts视图js--%>
    <script src="/js/Highcharts/code/highcharts.js"></script>
    <script src="/js/Highcharts/code/highcharts-3d.js"></script>
    <script src="/js/Highcharts/code/modules/exporting.js"></script>
    <script src="/js/Highcharts/code/modules/oldie.js"></script>
    <script src="/js/Highcharts/code/modules/cylinder.js"></script>
<%--支持中文--%>    
<script src="https://code.highcharts.com.cn/highcharts-plugins/highcharts-zh_CN.js"></script>
    

 <%--highcharts视图js表图--%>
 <div id="container1"style="44%;float: left"></div>
 <%--highcharts视图js圆圈图--%>
 <div id="container2"style="min-30%;height:400px;float: right"></div>

<script>

/*highcharts视图js表格图*/
    var chart1 = Highcharts.chart('container1', {
        chart: {
            type: 'cylinder',
            options3d: {
                enabled: true,
                alpha: 10,
                beta: 10,
                depth: 100,
                viewDistance: 50
            }
        },
        title: {
            text: '部门人数'
        },
        plotOptions: {
            series: {
                depth: 25,
                colorByPoint: true
            }
        },
        series: [{
            //seriesData是json数据
            data:seriesData,
            name: '部门人数',
            showInLegend: false
        }],
        xAxis:[{
            title: {
                enabled: true,
                text:"部门",
                style:"color:#000;"
            },
            categories:categories,
        }],
        yAxis:[{
            title: {
                enabled: true,
                text:"人数",
                style:"color:#000;"
            }
        }]
    })
    /*highcharts视图js圆圈图*/
    var chart2 = Highcharts.chart('container2', {
        chart: {
            type: 'pie',
            options3d: {
                enabled: true,
                alpha: 45,
                beta: 0
            },
            400,
            height:400,
        },
        title: {
            text: '部门人员占比'
        },
        tooltip: {
            pointFormat: '{series.name}: <b>{point.percentage:.1f}%</b>'
        },
        plotOptions: {
            pie: {
                allowPointSelect: true,
                cursor: 'pointer',
                depth: 35,
                dataLabels: {
                    enabled: true,
                    format: '{point.name}'
                }
            }
        },
        series: [{
            type: 'pie',
            name: '部门人员占比',
            //seriesData是json数据
            data: seriesData
        }]
    }); 

</script>

<script>
//highcharts视图的数据
    varseriesData =[];
    //highcharts视图的部门数据
    varcategories =[];
    //获取到highcharts视图的数据
    functionchartData() {
        $.ajax({
            url:'/employee/idxnd',
            type:'get',
            //必须设置成同步,不然categories赋不上值
async: false,
            success:function(data){
                seriesData=data;
                //设置部门categories数据
                for(vari = 0;i<data.length;i++){
                    categories.push(data[i][0]);
                }
            },
            error:function(error){
                console.log(error)
            }
        })
    }
    chartData();
</script>

[
  [
    "IT部",
    53],
  [
    "采购部",
    33],
  [
    "销售部",
    37],
  [
    "人事部",
    4],
  [
    "售后部",
    1],
  [
    "运货部",
    3]
]