title: How to find the max/min of a nested array in javascript?
body: <p>I want to find the maximum of a nested array, something like this:</p>
  
  <pre><code>a = [[1,2],[20,3]]
  d3.max(d3.max(a)) // 20
  </code></pre>
  
  <p>but my array contains a text field that I want to discard:</p>
  
  <pre><code>a = [["yz",1,2],["xy",20,3]]
  d3.max(a) // 20
  </code></pre>