Adaptive problem of echarts in Vue floating percentage div

insert an echarts china-map, into a floating div with a width of 50%. Please tell me how to make it adaptive.

< div id= "myChart" style= "float: left;width: 50%;" > < / div >

mounted () {

        this.drawLine();
    },
    methods: {
        drawLine() {
            // domecharts
            let myChart = echarts.init(document.getElementById("myChart"))
            // 
          var option = {
                title: {
                    text: "",
                    textStyle: {
                        fontSize: 30
                    },
                    x: "center"
                },
                tooltip: {
                    show: true,
                    formatter: function(params) {
                        return params.name + ":" + params.data["value"] + "%"
                    },
                },
                visualMap: {
                    min: 0,
                    max: 5.5,
                    left: "left",
                    top: "bottom",
                    text: ["%", ""], // 
                    calculable: true,
                    inRange:{
                        color:["-sharpffffff","-sharpd00000"]
                    }
                },
                series: [{
                    name: "",
                    type: "map",
                    map: "china",
                    roam: false,
                    label: {
                        show: false,
                    },
                    data:[
                        {name: "",value: 5.3 },
                        {name: "",value: 3.8 },
                        {name: "",value: 4.6 },
                        {name: "",value: 3.6 },
                        {name: "",value: 3.4 },
                        {name: "",value: 3.2 },
                        {name: "",value: 1.6 },
                        {name: "",value: 4.3 },
                        {name: "",value: 4.1 },
                        {name: "",value: 2.4 },
                        {name: "",value: 3.3 },
                        {name: "",value: 3.0 },
                        {name: "",value: 1 },
                        {name: "",value: 3.9 },
                        {name: "",value: 3.5 },
                        {name: "",value: 2.0 },
                        {name: "",value: 2.1 },
                        {name: "",value: 3.0 },
                        {name: "",value: 1.2 },
                        {name: "",value: 3.2 },
                        {name: "",value: 3.5 },
                        {name: "",value: 2.5 },
                        {name: "",value: 4.5 },
                        {name: "",value: 2.8 },
                        {name: "",value: 1.8 },
                        {name: "",value: 3.7 },
                        {name: "",value: 0.6 },
                        {name: "",value: 0.4 },
                        {name: "",value: 3.3 },
                        {name: "",value: 0.8 },
                        {name: "",value: 1.9 },
                        {name: "",value: 0 },
                        {name: "",value: 0 },
                        {name: "",value: 0}
                    ]
                }, ]
            };
            myChart.setOption(option)
            window.onresize = myChart.resize;
        }
    }
Mar.10,2021

window.onresize = function () {

myChart.resize();

}

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