title: How to use vAxis.direction to reverse the order of google graph
body: <p>I guess I can reverse the order of vertical axis of a graph using <code>vAxis.direction</code> by setting it to <code>-1</code>. But I am just learning and confused with the way to write it.</p>
  
  <p>Here is the current graph:</p>
  
  <p><img src="https://i.stack.imgur.com/D9AO9.jpg" alt="enter image description here"></p>
  
  <p>I want to <strong>reverse order the vertical axis</strong> with 0 at top and 80 at origin.</p>
  
  <p>Here is the existing code:</p>
  
  <pre><code>google.load('visualization', '1', {packages: ['corechart', 'line']});
  google.setOnLoadCallback(drawBackgroundColor);
  
  function drawBackgroundColor() {
        var data = new google.visualization.DataTable();
        data.addColumn('number', 'X');
        data.addColumn('number', 'Dogs');
  
        data.addRows([
          [0, 0],   [1, 10],  [2, 23],  [3, 17],  [4, 18],  [5, 9],
          [6, 11],  [7, 27],  [8, 33],  [9, 40],  [10, 32], [11, 35],
          [12, 30], [13, 40], [14, 42], [15, 47], [16, 44], [17, 48],
          [18, 52], [19, 54], [20, 42], [21, 55], [22, 56], [23, 57],
          [24, 60], [25, 50], [26, 52], [27, 51], [28, 49], [29, 53],
          [30, 55], [31, 60], [32, 61], [33, 59], [34, 62], [35, 65],
          [36, 62], [37, 58], [38, 55], [39, 61], [40, 64], [41, 65],
          [42, 63], [43, 66], [44, 67], [45, 69], [46, 69], [47, 70],
          [48, 72], [49, 68], [50, 66], [51, 65], [52, 67], [53, 70],
          [54, 71], [55, 72], [56, 73], [57, 75], [58, 70], [59, 68],
          [60, 64], [61, 60], [62, 65], [63, 67], [64, 68], [65, 69],
          [66, 70], [67, 72], [68, 75], [69, 80]
        ]);
  
        var options = {
          hAxis: {
            title: 'Time'
          },
          vAxis: {
            title: 'Popularity'
          },
          backgroundColor: '#f1f8e9'
        };
  
        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
        chart.draw(data, options);
      } 
  </code></pre>
  
  <p>Plese suggest how can I set <code>vAxis.direction</code> to <code>-1.</code> I tried a few code but of no help.</p>