Google Visualization group（）聚合函数返回空值

2024-05-10 • 问答

我有一列名为someNumber的列，其中包含空值和零。将google.visualization.data.group应用于此列时，我无法获得零来传递到表中，只能获得null。

.min和.max的{{3}}表示空值被忽略，但除了空值外，我似乎什么也没返回。

如何获得零来进入我的桌子？

谢谢专家！

工作示例：

// Load the Visualization API and the corechart package.
google.charts.load('current',{
  'packages': ['corechart','table','gauge','controls']
});

// Set a callback to run when the Google Visualization API is loaded.
google.charts.setOnLoadCallback(gchart0);

function gchart0() {
  drawChart();
};

function drawChart() {

  var result = [{
    "calendarWeek": "2017-W30","clnCount": 1,"someNumber": null //NOTE THIS IS SET TO NULL
  },{
    "calendarWeek": "2017-W30","clnCount": 3,"someNumber": 0 //NOTE THIS IS SET TO ZERO
  }];

  //Create DataTable
  var data = new google.visualization.DataTable();
  data.addColumn('string','Calendar Week');
  data.addColumn('number','Count');
  data.addColumn('number','Some Number');
  
  var dataArray = [];
  $.each(result,function(i,obj) {
    dataArray.push([
      obj.calendarWeek,obj.clnCount,obj.someNumber
    ]);
  });
  data.addRows(dataArray);

  //grouping 
  var groupView = google.visualization.data.group(data,[{
      column: 0,type: 'string'
    }],[{
        column: 1,aggregation: google.visualization.data.sum,type: 'number'
      },{
        column: 2,aggregation: google.visualization.data.min,type: 'number'
      }
    ]);

  //Options
  var options = {};

  // Instantiate and draw chart,passing in options.
  var chart = new google.visualization.Table(document.getElementById('chart_div'));
  chart.draw(groupView,options);

} //END  function drawChart()

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.1/jquery.min.js"></script>
<script src="https://www.gstatic.com/charts/loader.js"></script>

<div id="chart_div"></div>

您可以提供自己的自定义聚合功能。
聚合函数应接受值数组作为唯一参数。

在自定义求和函数中，我们将null替换为零

function customSum(values) {
  var sum = 0;
  values.forEach(function (value) {
    sum += value || 0;
  });
  return sum;
}

在自定义min函数中，当两个值均为Math.min时，null将返回零

function customMin(values) {
  var min = null;
  values.forEach(function (value) {
    min = Math.min(value,min);
  });
  return min;
}

请参阅以下工作片段...

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

// Set a callback to run when the Google Visualization API is loaded.
google.charts.setOnLoadCallback(gChart0);

function gChart0() {
  drawChart();
};

function drawChart() {

  var result = [{
    "calendarWeek": "2017-W30","clnCount": 1,"someNumber": null //NOTE THIS IS SET TO NULL
  },{
    "calendarWeek": "2017-W30","clnCount": 3,"someNumber": 0 //NOTE THIS IS SET TO ZERO
  }];

  //Create DataTable
  var data = new google.visualization.DataTable();
  data.addColumn('string','Calendar Week');
  data.addColumn('number','Count');
  data.addColumn('number','Some Number');

  var dataArray = [];
  $.each(result,function(i,obj) {
    dataArray.push([
      obj.calendarWeek,obj.clnCount,obj.someNumber
    ]);
  });
  data.addRows(dataArray);

  //grouping
  var groupView = google.visualization.data.group(data,[{
      column: 0,type: 'string'
    }],[{
        column: 1,aggregation: customSum,type: 'number'
      },{
        column: 2,aggregation: customMin,type: 'number'
      }
    ]);

  function customSum(values) {
    var sum = 0;
    values.forEach(function (value) {
      sum += value || 0;
    });
    return sum;
  }

  function customMin(values) {
    var min = null;
    values.forEach(function (value) {
      min = Math.min(value,min);
    });
    return min;
  }

  //Options
  var options = {};

  // Instantiate and draw chart,passing in options.
  var chart = new google.visualization.Table(document.getElementById('chart_div'));
  chart.draw(groupView,options);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.1/jquery.min.js"></script>
<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart_div"></div>

测试了最高版本，它也可以工作。这是要共享的代码：

function customMax(values) {
    var max = null;
    values.forEach(function (value) {
        max = Math.max(value,max);
    });
    return max;
}

Google Visualization group（）聚合函数返回空值

woxxx123 回答：Google Visualization group（）聚合函数返回空值

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