如何在图表中填充数据。js

Question

我正试图用图表可视化以下数据集。js

var data = 
{
    "count": 2,
    "result": {
        "2020-01-22": {
            "confirmed": 12,
            "deaths": 5,
            "recovered": 4
        },
        "2020-01-23": {
            "confirmed": 20,
            "deaths": 3,
            "recovered": 2
        }
    }
}

到目前为止，我已经知道如何使用日期作为标签。

  var chart = new Chart(ctx, {
        // The type of chart we want to create
        type: 'line',    
        data: { // mapping the dates as labels
            labels: Object.entries(data.result).map( (item) => item[0]),
            datasets: [{
                label: 'My First dataset',
                backgroundColor: 'rgb(255, 99, 132)',
                borderColor: 'rgb(255, 99, 132)',
                data: ??
            },{
                label: 'My Second dataset',
                backgroundColor: 'rgb(255, 99, 132)',
                borderColor: 'rgb(255, 99, 132)',
                data: ??
            },{
                label: 'My Third dataset',
                backgroundColor: 'rgb(255, 99, 132)',
                borderColor: 'rgb(255, 99, 132)',
                data: ??
            }]
        },    // Configuration options go here
        options: {}
    });

我想在这个图表中以三行显示“确认”、“死亡”和“恢复”的值。因此，我将包括三个不同的数据集，对吗？如何从json作为数组访问所需的信息来填充数据数组？

谢谢你的支持

Answer 1

只需将键和值映射到适当的数组，并将其作为数据集和标签使用。

var data = {
  "count": 2,
  "result": {
    "2020-01-22": {
      "confirmed": 12,
      "deaths": 5,
      "recovered": 4
    },
    "2020-01-23": {
      "confirmed": 20,
      "deaths": 3,
      "recovered": 2
    }
  }
}
var dates = Object.keys(data["result"]).map(x => x);
var confirm = Object.values(data.result).map(x => x.confirmed);
var deaths = Object.values(data.result).map(x => x.deaths);
var recovered = Object.values(data.result).map(x => x.recovered);


var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: dates,
    datasets: [{
        label: 'confirmed',
        data: confirm,
        backgroundColor: 'rgba(255, 99, 132, 0.2)',
        borderColor: 'rgba(255, 99, 132, 1)',
        borderWidth: 1
      },
      {
        label: 'Deaths',
        data: deaths,
        backgroundColor: 'rgba(54, 162, 235, 0.2)',


        borderColor: 'rgba(54, 162, 235, 1)',

        borderWidth: 1
      }, {
        label: 'recovered',
        data: recovered,
        backgroundColor: 'rgba(255, 206, 86, 0.2)',


        borderColor: 'rgba(255, 206, 86, 1)',

        borderWidth: 1
      }
    ]
  },
  options: {
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }]
    }
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<canvas id="myChart" width="100" height="50"></canvas>