title: min function in numpy array
body: <p>I am trying to find a min value from one dimensional numpy array which which looks like: </p>
  
  <pre><code>col = array(['6.7', '0.9', '1.3', '4', '1.8'],dtype='|S7'), 
  </code></pre>
  
  <p>using <code>col.min()</code>, which is not working.</p>
  
  <p>I tried as suggested on <a href="https://stackoverflow.com/questions/11321271/numpy-get-min-max-from-record-array-of-numeric-values">NumPy: get min/max from record array of numeric values</a> view function, it failed to recognize 'S7' as valid field.</p>
  
  <p>What is the best way to deal with this problem?  Should I have specified the data type while reading the values or while using the min function?</p>