How to change the format in the DataTable's Go

问题:

• I would like to change the format of the data in the DataTable in order to make it more flexible and the Chart is still the same with the first one.

Default:

['Year', 'Sales', 'Expenses'],
['2004',  1000,      400],
['2005',  1170,      460],
['2006',  660,       1120],
['2007',  1030,      540]

It must be:

['Year', '2004', '2005', '2006', '2007'],
['Sales', 1000, 1170, 660, 1030],
['Expenses', 400 ,460, 1120, 540]

Demo

---

HTML:

<div id="chart_div" style="width: 450px; height: 300px;"></div>

Javascript:

google.load("visualization", "1", {packages:["corechart"]});
  google.setOnLoadCallback(drawChart);
  function drawChart() {
    var data = google.visualization.arrayToDataTable([
      ['Year', 'Sales', 'Expenses'],
      ['2004',  1000,      400],
      ['2005',  1170,      460],
      ['2006',  660,       1120],
      ['2007',  1030,      540]
    ]);

    var options = {
      title: 'Company Performance'
    };

    var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
    chart.draw(data, options);
  }

回答1:

You must transpose array like: http://jsfiddle.net/krzysztof_safjanowski/Mw398/1/

var data = google.visualization.arrayToDataTable(transposeArray([
    ['Year', '2004', '2005', '2006', '2007'],
    ['Sales', 1000, 1170, 660, 1030],
    ['Expenses', 400, 460, 1120, 540]
]));

function transposeArray(array) {
  return array[0].map(function (col, i) {
    return array.map(function (row) {
      return row[i];
    });
  });
}

Before pass data to arrayToDataTable you mast prepare it in format that google charts will understand.

Transpose – http://en.wikipedia.org/wiki/Transpose

Method map – https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map