如何实现局部series重绘？echarts heatmap配置项内容和展示

如图，一共有两个series，包括一个heatmap和一个scatter，我想通过setInterval实现对scatter那个series的动态更新，但是我不想重新绘制heatmap（这里是模拟的数据，我自己的数据量特别大，heatmap绘制需要好几秒），但是在我的电脑上运行时，发现setOption会将两个series全部重新绘制，使得速度特别慢。 我尝试了设置不同的zlevel，但是没有效果，仍然会将两个series都重新绘制，请问有什么办法只re-render scatter那个series，而不重新绘制heatmap那个series？谢谢

      var hours = ['12a', '1a', '2a', '3a', '4a', '5a', '6a',
    '7a', '8a', '9a', '10a', '11a',
    '12p', '1p', '2p', '3p', '4p', '5p',
    '6p', '7p', '8p', '9p', '10p', '11p'
];
var days = ['Saturday', 'Friday', 'Thursday',
    'Wednesday', 'Tuesday', 'Monday', 'Sunday'
];

var data = [
    [0, 0, 5],
    [0, 1, 1],
    [0, 2, 0],
    [0, 3, 0],
    [0, 4, 0],
    [0, 5, 0],
    [0, 6, 0],
    [0, 7, 0],
    [0, 8, 0],
    [0, 9, 0],
    [0, 10, 0],
    [0, 11, 2],
    [0, 12, 4],
    [0, 13, 1],
    [0, 14, 1],
    [0, 15, 3],
    [0, 16, 4],
    [0, 17, 6],
    [0, 18, 4],
    [0, 19, 4],
    [0, 20, 3],
    [0, 21, 3],
    [0, 22, 2],
    [0, 23, 5],
    [1, 0, 7],
    [1, 1, 0],
    [1, 2, 0],
    [1, 3, 0],
    [1, 4, 0],
    [1, 5, 0],
    [1, 6, 0],
    [1, 7, 0],
    [1, 8, 0],
    [1, 9, 0],
    [1, 10, 5],
    [1, 11, 2],
    [1, 12, 2],
    [1, 13, 6],
    [1, 14, 9],
    [1, 15, 11],
    [1, 16, 6],
    [1, 17, 7],
    [1, 18, 8],
    [1, 19, 12],
    [1, 20, 5],
    [1, 21, 5],
    [1, 22, 7],
    [1, 23, 2],
    [2, 0, 1],
    [2, 1, 1],
    [2, 2, 0],
    [2, 3, 0],
    [2, 4, 0],
    [2, 5, 0],
    [2, 6, 0],
    [2, 7, 0],
    [2, 8, 0],
    [2, 9, 0],
    [2, 10, 3],
    [2, 11, 2],
    [2, 12, 1],
    [2, 13, 9],
    [2, 14, 8],
    [2, 15, 10],
    [2, 16, 6],
    [2, 17, 5],
    [2, 18, 5],
    [2, 19, 5],
    [2, 20, 7],
    [2, 21, 4],
    [2, 22, 2],
    [2, 23, 4],
    [3, 0, 7],
    [3, 1, 3],
    [3, 2, 0],
    [3, 3, 0],
    [3, 4, 0],
    [3, 5, 0],
    [3, 6, 0],
    [3, 7, 0],
    [3, 8, 1],
    [3, 9, 0],
    [3, 10, 5],
    [3, 11, 4],
    [3, 12, 7],
    [3, 13, 14],
    [3, 14, 13],
    [3, 15, 12],
    [3, 16, 9],
    [3, 17, 5],
    [3, 18, 5],
    [3, 19, 10],
    [3, 20, 6],
    [3, 21, 4],
    [3, 22, 4],
    [3, 23, 1],
    [4, 0, 1],
    [4, 1, 3],
    [4, 2, 0],
    [4, 3, 0],
    [4, 4, 0],
    [4, 5, 1],
    [4, 6, 0],
    [4, 7, 0],
    [4, 8, 0],
    [4, 9, 2],
    [4, 10, 4],
    [4, 11, 4],
    [4, 12, 2],
    [4, 13, 4],
    [4, 14, 4],
    [4, 15, 14],
    [4, 16, 12],
    [4, 17, 1],
    [4, 18, 8],
    [4, 19, 5],
    [4, 20, 3],
    [4, 21, 7],
    [4, 22, 3],
    [4, 23, 0],
    [5, 0, 2],
    [5, 1, 1],
    [5, 2, 0],
    [5, 3, 3],
    [5, 4, 0],
    [5, 5, 0],
    [5, 6, 0],
    [5, 7, 0],
    [5, 8, 2],
    [5, 9, 0],
    [5, 10, 4],
    [5, 11, 1],
    [5, 12, 5],
    [5, 13, 10],
    [5, 14, 5],
    [5, 15, 7],
    [5, 16, 11],
    [5, 17, 6],
    [5, 18, 0],
    [5, 19, 5],
    [5, 20, 3],
    [5, 21, 4],
    [5, 22, 2],
    [5, 23, 0],
    [6, 0, 1],
    [6, 1, 0],
    [6, 2, 0],
    [6, 3, 0],
    [6, 4, 0],
    [6, 5, 0],
    [6, 6, 0],
    [6, 7, 0],
    [6, 8, 0],
    [6, 9, 0],
    [6, 10, 1],
    [6, 11, 0],
    [6, 12, 2],
    [6, 13, 1],
    [6, 14, 3],
    [6, 15, 4],
    [6, 16, 0],
    [6, 17, 0],
    [6, 18, 0],
    [6, 19, 0],
    [6, 20, 1],
    [6, 21, 2],
    [6, 22, 2],
    [6, 23, 6]
];

var data2 = [
    [1, 2, 5],
    [2, 2, 6],
    [3, 3, 7]
]
var count = 0

data = data.map(function(item) {
    return [item[1], item[0], item[2] || '-'];
});

option = {
    tooltip: {
        position: 'top'
    },
    animation: false,
    grid: {
        height: '30%',
        y: '10%'
    },
    xAxis: {
        type: 'category',
        data: hours,
        splitArea: {
            show: true
        }
    },
    yAxis: {
        type: 'category',
        data: days,
        splitArea: {
            show: true
        }
    },
    visualMap: [{
        min: 0,
        max: 10,
        calculable: true,
        orient: 'horizontal',
        left: 'center',
        bottom: '15%',
        seriesIndex: [0],
        show: true
    }, {
        left: 'right',
        top: '10%',
        dimension: 2,
        min: 5,
        max: 8,
        itemWidth: 30,
        itemHeight: 120,
        calculable: false,
        show: false,
        precision: 0.1,
        inRange: {
            symbolSize: [20, 40]
        },
        seriIndex: [1, 2]
    }],
    series: [{
            name: 'Punch Card',
            type: 'heatmap',
            data: data,
            label: {
                normal: {
                    show: true
                }
            },
            itemStyle: {
                emphasis: {
                    shadowBlur: 10,
                    shadowColor: 'rgba(0, 0, 0, 0.5)'
                }
            },
            zlevel: 2
        },
        {
            name: 'before',
            type: 'scatter',
            color: 'red',
            data: data2,
            zlevel: 3
        },
    ]
};


setInterval(function() {
    for (let i = 0; i < 3; i++) {
        data2[i][0] += (count++ % 2) * 2 - 1
    }

    myChart.setOption({
        series: [{
            data: data
        }, {
            data: data2
        }]
    });
}, 1000);