title: How to not show x axis value in tooltip
body: <p>I would like to not show the x axis value in tooltip for line chart using google visualization api. Does anyone know how to do that? I would like series 1 and 2 in the code below to have a tooltip that shows only the vertical axis value (Test)</p>
  
  <pre><code>var data = new google.visualization.DataTable();
          data.addColumn('date', 'Date Logged');
          data.addColumn('number', 'Test');
          data.addColumn('string', 'State');
           data.addColumn('number', null);
            data.addColumn('number', null);
  
  
  
          for (var i = 0; i &lt; dataValues.length; i++) {
              data.addRow(//getting this from db);
          }
  
       var monthformatter = new google.visualization.DateFormat({pattern: "MMM d, y"});
      monthformatter.format(data, 0);
  
        // Define a category picker control 
     var categoryPicker2 = new google.visualization.ControlWrapper({
        'controlType': 'CategoryFilter',
        'containerId': 'control2',
        'options': {
          'filterColumnLabel': 'State',
          'ui': {
          'labelStacking': 'vertical',
            'allowTyping': false,
            'allowMultiple': false,
            'caption' : 'All'
  
          }
        }
      });
  
      chart = new google.visualization.ChartWrapper({
        'chartType': 'ScatterChart',
        'containerId': 'chart1',
        'options': {
          'title': 'Test',
            'width': 500,
            'height': 500,
            'legend': 'none',
            'pointSize': 5,
            'vAxis': { 'title': 'Test', 'titleTextStyle': { 'color': 'red'}},
            'hAxis': { 'format': 'MMM d, y', 'title': 'Date', 'titleTextStyle': { 'color': 'red'} },
           'interpolateNulls': true,
          'pieSliceText': 'label',
          'series': {
            '0': { 'color': 'blue' },
            '1': { 'color': 'red', 'lineWidth': 3, 'pointSize': 0, 'visibleInLegend': 'false' },
            '2': { 'color': 'red', 'lineWidth': 3, 'pointSize': 0, 'visibleInLegend': 'false'},
          }
        },
  
  
        'view': {'columns': [0, 1, 3, 4]}
      });
  
  
  
       // Create a dashboard
      new google.visualization.Dashboard(document.getElementById('dashboard')).
          bind([categoryPicker2], [chart]).
          // Draw the entire dashboard.
          draw(data);
  </code></pre>