Google Visualization Chart Not Showing First Colum

问题:

I am having an issue with the Google Visualization API in that some of the data in the chart is not showing. The chart is fairly simple, it has 4 columns and two rows.

http://savedbythegoog.appspot.com/?id=ae0853b788af3292b5547a5b7f1224aed76abfff

 function drawVisualization() {
      // Create and populate the data table.

      var data_table = new google.visualization.DataTable();
      data_table.addColumn({"type": "date","label": "Date"});
      data_table.addColumn({"type": "number","label": "A"});
      data_table.addColumn({"type": "number","label": "B"});
      data_table.addColumn({"type": "number","label": "C"});

      data_table.addRow([{v: new Date(2013, 5, 26)}, {v: 1}, {v: 0}, {v: 0}]);
      data_table.addRow([{v: new Date(2013, 5, 27)}, {v: 2}, {v: 1}, {v: 0.5}]);

      var chart = new google.visualization.ColumnChart(document.getElementById('visualization'));
      chart.draw(data_table, {
          legend: "bottom"
      });

  }

When generated, the chart shows nothing for the first row (2013-5-26), and shows only the values of 2 and 1 for the second row (omitting 0.5).

I suspect this could be similar to Google Column Chart Missing data

Does anyone have any ideas?

回答1:

So it seems Google have provided the solution somewhat...

https://developers.google.com/chart/interactive/docs/customizing_axes#Discrete_vs_Continuous

Help! My chart has gone wonky!

My domain axis type is not string but I still want a discrete domain axis:

and this makes you terribly upset, then you can do one of the following:

1. Change the type of your first data table column to string.
2. Use a DataView as adapter to convert the type of your first data table column to string:

So the solution to the above chart was to add:

//Create a DataView from the data_table
var dataView = new google.visualization.DataView(data_table);

//Set the first column of the dataview to format as a string, and return the other columns [1, 2 and 3]
dataView.setColumns([{calc: function(data, row) { return data.getFormattedValue(row, 0); }, type:'string'}, 1, 2, 3]);

So the whole function became:

function drawVisualization() {
var data_table = new google.visualization.DataTable();
  data_table.addColumn({"type": "date","label": "Date"});
  data_table.addColumn({"type": "number","label": "A"});
  data_table.addColumn({"type": "number","label": "B"});
  data_table.addColumn({"type": "number","label": "C"});

  data_table.addRow([{v: new Date(2013, 5, 26)}, {v: 1}, {v: 0}, {v: 0}]);
  data_table.addRow([{v: new Date(2013, 5, 27)}, {v: 2}, {v: 1}, {v: 0.5}]);

  //Create a DataView from the data_table
  var dataView = new google.visualization.DataView(data_table);

  //Set the first column of the dataview to format as a string, and return the other columns [1, 2 and 3]
  dataView.setColumns([{calc: function(data, row) { return data.getFormattedValue(row, 0); }, type:'string'}, 1, 2, 3]);
  var chart = new google.visualization.ColumnChart(document.getElementById('visualization'));
  chart.draw(dataView, {
      legend: "bottom"
  });
}