谷歌图表：在仪表板中获取条形图的列数

Question

我有一个如下所示的 JSON 数据来在谷歌图表中构建仪表板。 我想绘制一个每月条形图，其中 x 轴作为 scan_time（月份），y 轴作为进入该月的 tag_id 的计数。 tag_ids 可以重复。

以 JSON 格式输入数据：

 [ 
       {  
          "tag_id":"04:0f",
          "scan_time":"2016-09-29 06:47:47",
       },
       {  
          "tag_id":"04:0f",
          "scan_time":"2016-09-29 14:48:42",
       },
       {  
          "tag_id":"99:9n",
          "scan_time":"2016-10-29 06:47:47",
       },
       {  
          "tag_id":"05:m8",
          "scan_time":"2016-11-29 06:48:42",
       }
    ]

类似

Month       Count
    Sept        2
    Oct         1
    Nov         1

Answer 1

一旦将 JSON 加载到 DataTable 中，

使用数据处理方法 --> group()

返回一个聚合的DataTable

请参阅以下工作 sn-p，
group 方法将第一列转换为“月”字符串，
并汇总每个“月”的标签 ID 计数

google.charts.load('current', {
  callback: drawChart,
  packages:['table']
});

function drawChart() {
  var data = google.visualization.arrayToDataTable([
    ['date', 'tag_id'],
    [new Date('2016-09-29 06:47:47'), '04:0f'],
    [new Date('2016-09-29 14:48:42'), '04:0f'],
    [new Date('2016-10-29 06:47:47'), '99:9n'],
    [new Date('2016-11-29 06:48:42'), '05:m8'],
  ]);

  var formatDate = new google.visualization.DateFormat({pattern: 'MMMM'});

  var dataGroup = google.visualization.data.group(
    data,

    // group by column
    [{
      column: 0,
      label: 'Month',
      modifier: function (val) {
        return formatDate.formatValue(val);
      },
      type: 'string'
    }],

    // agg columns
    [{
      aggregation: google.visualization.data.count,
      column: 1,
      label: 'Tag Count',
      type: 'number'
    }]
  );

  var table = new google.visualization.Table(document.getElementById('chart_div'));
  table.draw(dataGroup);
}

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart_div"></div>

编辑

使用 DataView 对行进行自定义排序

var view = new google.visualization.DataView(dataGroup);
view.setRows([2, 1, 0]);

使用view 绘制表格图表，以及任何其他图表...

下面的 sn-p 包含一个 ColumnChart...

google.charts.load('current', {
  callback: drawChart,
  packages:['corechart', 'table']
});

function drawChart() {
  var data = google.visualization.arrayToDataTable([
    ['date', 'tag_id'],
    [new Date('2016-09-29 06:47:47'), '04:0f'],
    [new Date('2016-09-29 14:48:42'), '04:0f'],
    [new Date('2016-10-29 06:47:47'), '99:9n'],
    [new Date('2016-11-29 06:48:42'), '05:m8'],
  ]);

  var formatDate = new google.visualization.DateFormat({pattern: 'MMMM'});

  var dataGroup = google.visualization.data.group(
    data,

    // group by column
    [{
      column: 0,
      label: 'Month',
      modifier: function (val) {
        return formatDate.formatValue(val);
      },
      type: 'string'
    }],

    // agg columns
    [{
      aggregation: google.visualization.data.count,
      column: 1,
      label: 'Tag Count',
      type: 'number'
    }]
  );

  var view = new google.visualization.DataView(dataGroup);
  view.setRows([2, 1, 0]);

  var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
  chart.draw(view);

  var table = new google.visualization.Table(document.getElementById('table_div'));
  table.draw(view);
}

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart_div"></div>
<div id="table_div"></div>

编辑 2

使用 ChartWrapper，将 view 设置为 dataTable 属性，例如

var table = new google.visualization.ChartWrapper({
  chartType: 'Table',
  containerId: 'table_div',
  dataTable: view
});

请参阅以下工作 sn-p...

google.charts.load('current', {
  callback: drawChart,
  packages:['corechart', 'table']
});

function drawChart() {
  var data = google.visualization.arrayToDataTable([
    ['date', 'tag_id'],
    [new Date('2016-09-29 06:47:47'), '04:0f'],
    [new Date('2016-09-29 14:48:42'), '04:0f'],
    [new Date('2016-10-29 06:47:47'), '99:9n'],
    [new Date('2016-11-29 06:48:42'), '05:m8'],
  ]);

  var formatDate = new google.visualization.DateFormat({pattern: 'MMMM'});

  var dataGroup = google.visualization.data.group(
    data,

    // group by column
    [{
      column: 0,
      label: 'Month',
      modifier: function (val) {
        return formatDate.formatValue(val);
      },
      type: 'string'
    }],

    // agg columns
    [{
      aggregation: google.visualization.data.count,
      column: 1,
      label: 'Tag Count',
      type: 'number'
    }]
  );

  var view = new google.visualization.DataView(dataGroup);
  view.setRows([2, 1, 0]);

  var chart = new google.visualization.ChartWrapper({
    chartType: 'ColumnChart',
    containerId: 'chart_div',
    dataTable: view
  });
  chart.draw();

  var table = new google.visualization.ChartWrapper({
    chartType: 'Table',
    containerId: 'table_div',
    dataTable: view
  });
  table.draw();
}

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart_div"></div>
<div id="table_div"></div>