javascript - Echart报错：无法找到‘get’方法

var myChart = echarts.init(document.getElementById('main'));

    var dd = [
        //员工名字:String  客户数量:Float  折扣单数:Float  折扣金额:Double
        
            {
                Ename: '员工1',
                Cnum: ['122', '234', '145', '219', '123', '311', '222', '221', '322', '112', '324', '256'],
                Onum: ['112', '123', '119', '333', '444', '555', '666', '777', '888', '456', '234', '342'],
                Ofee: ['12234', '23455', '11234', '22413', '11543', '24351', '11980', '32331', '23214', '33214', '11324', '14235']
            },
            {
                Ename: '员工2',
                Cnum: ['122', '234', '145', '219', '123', '311', '222', '221', '322', '112', '324', '256'],
                Onum: ['112', '123', '119', '333', '444', '555', '666', '777', '888', '456', '234', '342'],
                Ofee: ['12234', '23455', '11234', '22413', '11543', '24351', '11980', '32331', '23214', '33214', '11324', '14235']
            },
            {
                Ename: '员工3',
                Cnum: ['122', '234', '145', '219', '123', '311', '222', '221', '322', '112', '324', '256'],
                Onum: ['112', '123', '119', '333', '444', '555', '666', '777', '888', '456', '234', '342'],
                Ofee: ['12234', '23455', '11234', '22413', '11543', '24351', '11980', '32331', '23214', '33214', '11324', '14235']
            }
        
    ];

    var option = {
        title: {
            text: '业务打折分析折线图'
        },
        tooltip: {
            trigger: 'axis'
        },
        legend: {
            data: ['员工A', '员工B', '员工C', '员工D', '员工E']
        },
        grid: {
            left: '3%',
            right: '4%',
            bottom: '3%',
            containLabel: true
        },
        toolbox: {
            feature: {
                saveAsImage: {}
            }
        },
        xAxis: {
            type: 'category',
            boundaryGap: false,
            data: ['一月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '十一月', '十二月']
        },
        yAxis: {
            type: 'value'
        }
    };

    var chartdata = [];
    for (var i = 0; i < dd.length; i++) {
        chartdata.push({
            name:dd[i].Ename,
            type: 'line',
            stack: '总量',
            data: dd[i].Cnum
        });
    }

    option.series = chartdata;
    myChart.setOption(option);