title: How do you get JSON data and create a line chart with d3.js?
body: <p>I have a php script that echoes a large JSON array.  This is a very small part of it:</p>
  
  <pre><code>{
  "BR_RioDeJaneiro": [
      {
          "timeRange": "12:00:00 AM-12:19:59 AM",
          "average": "4.3653"
      },
      {
          "timeRange": "12:20:00 AM-12:39:59 AM",
          "average": "4.5386"
      }
  ]
  }
  </code></pre>
  
  <p>The time range actually goes up to <code>11:50:00 AM-11:59:59 PM</code>.  I want the <code>timeRange</code> to be the domain and the <code>average</code> to be the range.  I would like to create a line chart that visualizes the averages during each time range.  I know there's a <code>d3.json()</code> function that can be used to get the json data but I'm having a hard time understanding how you can set up the domain, range and create the visualization.  Thanks.</p>