title: How to assign labels to the x-axis using drupal module chart?
body: <p>I am trying to create a bar chart using <a href="https://www.drupal.org/project/chart" rel="nofollow">chart</a>, a drupal module using <a href="https://developers.google.com/chart/image/" rel="nofollow">google chart tools</a>.</p>
  
  <p>I can't figure out how to put labels under the bars. The labels should be 'a', 'b', and so on. For some reason, only the first label, 'a' is showing up on the x-axis and its straight in the center of the graph.
  Here is my code:</p>
  
  <pre><code>$chart = array(
    '#chart_id' =&gt; 'test_chart2',
    '#title' =&gt; chart_title(t('Bar Chart'), '0000ee', 15),
    '#type' =&gt; CHART_TYPE_BAR_V_GROUPED,
    '#size' =&gt; chart_size(400, 200),
    '#grid_lines' =&gt; chart_grid_lines(10, 10),
    '#bar_size' =&gt; chart_bar_size(25, 5),
  
   );
  
    $chart['#data'][] = array(10);
    $chart['#data'][] = array(20);
    $chart['#data'][] = array(30);
    $chart['#data'][] = array(40);
    $chart['#data'][] = array(50);
    $chart['#data'][] = array(60);
    $chart['#data'][] = array(70);
    $chart['#data'][] = array(80);
  
    $chart['#data_colors'][] = chart_unique_color('test_a');
    $chart['#data_colors'][] = chart_unique_color('test_b');
    $chart['#data_colors'][] = chart_unique_color('test_c');
  
    $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][0][] =   chart_mixed_axis_range_label(0, 200);
    $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][3][] = chart_mixed_axis_label(t('Hours'), 95);
  
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][4][] = chart_mixed_axis_label(t('a'));
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][5][] = chart_mixed_axis_label(t('b'));
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][6][] = chart_mixed_axis_label(t('c'));
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][7][] = chart_mixed_axis_label(t('d'));  
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][8][] = chart_mixed_axis_label(t('e'));
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][9][] = chart_mixed_axis_label(t('f'));
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][10][] = chart_mixed_axis_label(t('g'));
    $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][11][] = chart_mixed_axis_label(t('h'));
  
  
    return chart_render($chart);
  </code></pre>