title: read csv/tsv with no header line in D3
body: <p>I have CSV data which looks something like:</p>
  <h3>Data</h3>
  <pre><code>1,1,10
  1,2,50
  1,3,5
  etc...
  </code></pre>
  <p>And I am trying to read in the data. However, my initial data does not contain a header row (as seen above) so it is taking the first data row to be the header (1,1,10). Is there anyway around this. I want to set the header names after I read the data</p>
  <h3>Javascript</h3>
  <pre><code>d3.csv(&quot;data/testnh.csv&quot;, function(data) {
      console.log(data);
  }
  </code></pre>
  <p>Thanks!</p>