Chartjs折线图选项显示每个数据点之间的增加和减少百分比

<canvas id="myChart"></canvas>

var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
    type: 'line',
    data: {
        // 数据
    },
    options: {
        // 选项
    }
});

options: {
    tooltips: {
        callbacks: {
            label: function(tooltipItem, data) {
                var dataset = data.datasets[tooltipItem.datasetIndex];
                var currentValue = dataset.data[tooltipItem.index];
                var previousValue = dataset.data[tooltipItem.index - 1] || 0;
                var percentage = ((currentValue - previousValue) / previousValue * 100).toFixed(2);
                return currentValue + ' (' + percentage + '%)';
            }
        }
    }
}