禁用图表上从工具提示到点位置的线条

var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
    type: 'line',
    data: {
        labels: ['January', 'February', 'March', 'April', 'May', 'June', 'July'],
        datasets: [{
            label: 'My First dataset',
            backgroundColor: 'rgb(75, 192, 192)',
            borderColor: 'rgb(75, 192, 192)',
            data: [0, 10, 5, 2, 20, 30, 45]
        }]
    },
    options: {
        tooltips: {
            mode: 'index',
            intersect: false,
            callbacks: {
                label: function(tooltipItem, data) {
                    return data.datasets[tooltipItem.datasetIndex].label + ': ' + data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
                }
            }
        },
        hover: {
            mode: 'index',
            intersect: false
        }
    }
});

Highcharts.chart('container', {
    chart: {
        type: 'line'
    },
    title: {
        text: 'My Chart'
    },
    xAxis: {
        categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul']
    },
    yAxis: {
        title: {
            text: 'Values'
        }
    },
    series: [{
        name: 'My Series',
        data: [1, 3, 2, 4, 5, 6, 7]
    }],
    tooltip: {
        crosshairs: false
    }
});

// 创建SVG容器
var svg = d3.select('svg');

// 创建数据点
var data = [10, 20, 30, 40, 50];

// 创建工具提示
var tooltip = d3.select('body').append('div')
    .attr('class', 'tooltip')
    .style('opacity', 0);

// 创建数据点
svg.selectAll('circle')
    .data(data)
    .enter().append('circle')
    .attr('cx', function(d, i) { return i * 50 + 50; })
    .attr('cy', function(d) { return 200 - d; })
    .attr('r', 5)
    .on('mouseover', function(d) {
        tooltip.transition()
            .duration(200)
            .style('opacity', .9);
        tooltip.html(d)
            .style('left', (d3.event.pageX + 5) + 'px')
            .style('top', (d3.event.pageY - 28) + 'px');
    })
    .on('mouseout', function(d) {
        tooltip.transition()
            .duration(500)
            .style('opacity', 0);
    });