title: xmlns shows that URI is not absolute, how to have this type of namespace specific xml parsing to r?
body: <p>I am a newbie to R and xml, and i would like to fetch some data from a webpage, however, my code fails due to (I guess) xml namespace, (correct me if i am wrong), what should i do to make my code ok?</p>
  
  <pre><code>data &lt;- "http://usda.mannlib.cornell.edu/usda/current/wasde/wasde-01-12-2015.xml"
  path &lt;- "//sr15//matrix1//attribute4[@attribute4='Ending Stocks']//m1_year_group[@market_year4='2013/14 Est.']//Cell"
  getNodeSet(data,path)
  </code></pre>
  
  <p>returns NULL</p>
  
  <p>Nevertheless, if I parse a different xml without <strong>xmlns="wasde"</strong>, it's possible to read</p>
  
  <pre><code>data2 &lt;- "http://usda.mannlib.cornell.edu/usda/waob/wasde//2010s/2014/wasde-12-10-2014.xml"
  
  getNodeSet(data2,path)
  </code></pre>
  
  <p>Any thought? Many thanks in advance.</p>