title: How to extract numbers from text?
body: <p>i have the flowing text string:</p>
  
  <pre><code>string &lt;- "['CBOE SHORT-TERM VIX FUTURE DEC 2016', 81.64],\n\n    ['CBOE SHORT-TERM VIX FUTURE JAN 2017', 18.36]"
  </code></pre>
  
  <p>is there a simple way of extracting numerical elements from text without having to use:</p>
  
  <pre><code>string_table &lt;- strsplit(string, " ")
  </code></pre>
  
  <p>and then select n-th element and continue to <code>strsplit</code> until i have what i need. </p>
  
  <p>the result should be:</p>
  
  <pre><code>result &lt;- c(2016, 81, 64, 2017, 18, 36)
  </code></pre>
  
  <p>thank you. </p>