求助 echarts 节点如何拖动

[ttigerdna]

按照https://www.w3cschool.cn/echarts_tutorial/echarts_tutorial-d5b128yu.html文章
我怎么也弄不出来
我的代码：

myChart = echarts.init(document.getElementById('echartsMain'));
			
			//
			option = {
			    title: {
			        text: '风区70米风速',
			        subtext: ''
			    },
			    tooltip: {
			        trigger: 'axis'
			    },
			    grid: {
			    },
			    legend: {
			        data:['风速']
			    },
			    toolbox: {
			        show: true,
			        feature: {
			        	dataZoom : {show: true},
			        	restore : {show: true},
			            saveAsImage: {}
			        }
			    },
			    xAxis:  {
			        type: 'category',
			        boundaryGap: false,
			        //data: ['周一','周二','周三','周四','周五','周六','周日']
			    	data: []
			    },
			    yAxis: {
			        type: 'value',
			        axisLabel: {
			            formatter: '{value} m/s'
			        }
			    },
			    dataZoom: [
			        {
			            type: 'slider',
			            xAxisIndex: 0,
			            filterMode: 'empty'
			        },
			        {
			            type: 'slider',
			            yAxisIndex: 0,
			            filterMode: 'empty'
			        },
			        {
			            type: 'inside',
			            xAxisIndex: 0,
			            filterMode: 'empty'
			        },
			        {
			            type: 'inside',
			            yAxisIndex: 0,
			            filterMode: 'empty'
			        }
			    ],
			    series: [
			        {
			        	name:'风速',
			        	id: 'a',
			            type:'line',
			            //data:[11, 11, 15, 13, 12, 13, 10],
			            data:[],
			            markPoint: {
			                data: [
			                    {type: 'max', name: '最大值'},
			                    {type: 'min', name: '最小值'}
			                ]
			            },
			            markLine: {
			                data: [
			                    {type: 'average', name: '平均值'}
			                ]
			            }
			        }
			    ]
			};
			//
			
			myChart.on('dataZoom', updatePosition);
myChart.setOption(option);
			myChart.hideLoading();

myChart.setOption({
					            graphic: echarts.util.map(windv70, function (item, dataIndex) {
					                return {
					                    type: 'circle',
					                    position: myChart.convertToPixel('grid', item),
					                    shape: {
					                        cx: 0,
					                        cy: 0,
					                        r: symbolSize / 2
					                    },
					                    invisible: true,
					                    draggable: true,
					                    ondrag: echarts.util.curry(onPointDragging, dataIndex),
					                    onmousemove: echarts.util.curry(showTooltip, dataIndex),
					                    onmouseout: echarts.util.curry(hideTooltip, dataIndex),
					                    z: 100
					                };
					            })
					        });

window.addEventListener('resize', updatePosition);

function updatePosition() {
		    myChart.setOption({
		        graphic: echarts.util.map(windv70, function (item, dataIndex) {
		            return {
		                position: myChart.convertToPixel('grid', item)
		            };
		        })
		    });
		}

		function showTooltip(dataIndex) {
		    myChart.dispatchAction({
		        type: 'showTip',
		        seriesIndex: 0,
		        dataIndex: dataIndex
		    });
		}

		function hideTooltip(dataIndex) {
		    myChart.dispatchAction({
		        type: 'hideTip'
		    });
		}

		function onPointDragging(dataIndex, dx, dy) {
			windv70[dataIndex] = myChart.convertFromPixel('grid', this.position);

		    // Update data
		    myChart.setOption({
		        series: [{
		            id: 'a',
		            data: windv70
		        }]
		    });
		}