title: Parsing a JSON object to get column data
body: <p>Say I have data in a JSON object formatted similar to...</p>
  
  <pre><code>{"data":
         [["X","Y","Z"], 
         ["52","23","10"],
         ["46","65","32"]]
  }
  </code></pre>
  
  <p>So essentially, each row takes the form <code>[X, Y, Z]</code>.</p>
  
  <p>What would be the easiest way to then access an entire "column" or vector of data?  For example, let's assume the "X", "Y", and "Z" is a header row, and I want to access all of the "X" data.  </p>
  
  <p>Do I need to iterate over the entire object somehow to retrieve the first member of each element, which would correspond to the "X" column?</p>
  
  <p>I'd like to do this in JavaScript if possible.  </p>
  
  <p>Thanks much for any assistance!</p>