var symbolSize = 20;
var data = [[15, 0], [-50, 10], [-56.5, 20], [-46.5, 30], [-22.1, 40]];

option = {
    title: {
        text: 'Try Dragging these Points'
    },
    tooltip: {
        triggerOn: 'none',
        formatter: function (params) {
            return 'X: ' + params.data[0].toFixed(2) + '<br>Y: ' + params.data[1].toFixed(2);
        }
    },
    grid: {
    },
    xAxis: {
        min: -100,
        max: 80,
        type: 'value',
        axisLine: {onZero: false}
    },
    yAxis: {
        min: -30,
        max: 60,
        type: 'value',
        axisLine: {onZero: false}
    },
    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: [
        {
            id: 'a',
            type: 'line',
            smooth: true,
            symbolSize: symbolSize,
            data: data
        }
    ]
};


setTimeout(function () {
    // Add shadow circles (which is not visible) to enable drag.
    myChart.setOption({
        graphic: echarts.util.map(data, 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
            };
        })
    });
}, 0);

window.addEventListener('resize', updatePosition);

myChart.on('dataZoom', updatePosition);

function updatePosition() {
    myChart.setOption({
        graphic: echarts.util.map(data, 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) {
    data[dataIndex] = myChart.convertFromPixel('grid', this.position);

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