Echartsjs 柱形图加折线图 启用datazoom，滑动图标之后更新数据，不能覆盖原数据的问题。echarts 柱状配置项内容和展示

Echartsjs 柱形图加折线图 启用datazoom，滑动图标之后更新数据，不能覆盖原数据的问题。旧的折线会出现在图表上，目前解决办法：1、setOption之前调用 .clear()，2、给 series data 空数组，然后setOption，再给data新数组，再次setOption

      option = {
    dataZoom: {
        type: 'slider',
        show: true,
        xAxisIndex: [0],
        start: 1,
        end: 35

    },
    xAxis: [{
            type: 'category',
            boundaryGap: true,
            data: [1, 2, 3, 4, 5, 6, 7, 8]
        },
        {
            type: 'category',
            boundaryGap: true,
            data: (function() {
                var res = [];
                var len = 10;
                while (len--) {
                    res.push(10 - len - 1);
                }
                return res;
            })()
        }
    ],
    yAxis: [{
            type: 'value',
            scale: true,
            name: '价格',
            max: 30,
            min: 0,
            boundaryGap: [0.2, 0.2]
        },
        {
            type: 'value',
            scale: true,
            name: '预购量',
            max: 50,
            min: 0,
            boundaryGap: [0.2, 0.2]
        }
    ],
    series: [{
            name: '预购队列',
            type: 'bar',
            xAxisIndex: 1,
            yAxisIndex: 1,
            data: [1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 81, 2, 3, 4, 5, 6, 7, 8]
        },
        {
            name: '最新成交价',
            type: 'line',
            data: [1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 81, 2, 3, 4, 5, 6, 7, 81, 2, 3, 4, 5, 6, 7, 8]
        }
    ]
};

setInterval(function() {
    var abc = [];
    var bcd = [];
    option.series[0].data = abc,
        option.series[1].data = bcd,

        abc.push(10);
    bcd.push(3);
    myChart.clear();
    myChart.setOption(option, true);






}, 5000);