title: Google Charts-Code for Category Filter
body: <p>Was trying out the Google Chart function codes.  I'm currently trying to create a line chart with a category filter.  Here's my code:</p>
  
  <pre><code>function drawVisualization() {
  // Prepare the data.
  var data = google.visualization.arrayToDataTable([
  ['x', 'Cats', 'Blanket 1', 'Blanket 2'],
  ['A',   1,       1,           0.5],
  ['B',   2,       0.5,         1],
  ['C',   4,       1,           0.5],
  ['D',   8,       0.5,         1],
  ['E',   7,       1,           0.5],
  ['F',   7,       0.5,         1],
  ['G',   8,       1,           0.5],
  ['H',   4,       0.5,         1],
  ['I',   2,       1,           0.5],
  ['J',   3.5,     0.5,         1],
  ['K',   3,       1,           0.5],
  ['L',   3.5,     0.5,         1],
  ['M',   1,       1,           0.5],
  ['N',   1,       0.5,         1]
  ]);
  
  // Define a category picker for the 'category' column.
  var categoryPicker = new google.visualization.ControlWrapper({
  'controlType': 'CategoryFilter',
  'containerId': 'control1',
  'options': {
    'filterColumnLabel': 'item',
    'ui': {
      'allowTyping': false,
      'allowMultiple': true,
      'selectedValuesLayout': 'belowStacked'
    }
  },
  // Define an initial state, i.e. a set of metrics to be initially selected.
  'state': {'selectedValues': ['Cats', 'Blanket 1', 'Blanket 2']}
  });
  
  // Define a line chart.
  var LineChart = new google.visualization.ChartWrapper({
  'chartType': "Line",
  'containerId': 'chart1',
  'options': {
    'width': 500,
    'height': 400,
    'vAxis': {maxValue: 10}
  }
  });
  
  // Create the dashboard.
  var dashboard = new           google.visualization.Dashboard(document.getElementById('dashboard')).
  // Configure the category picker to affect the line chart
  bind(categoryPicker, LineChart).
  // Draw the dashboard
  draw(data);
  }
  </code></pre>
  
  <p>Can anyone tell me why my graph is not displaying inside the Google Playground.  I know it must be a simple mistake, but I'm drawing a blank.</p>
  
  <p>Thanks for any help!
  ​ </p>