title: Scipy: Pearson's correlation always returning 1
body: <p>I am using Python library scipy to calculate Pearson's correlation for two float arrays. The returned value for coefficient is always 1.0, even if the arrays are different. For example:</p>
  
  <pre><code>[-0.65499887  2.34644428]
  [-1.46049758  3.86537321]
  </code></pre>
  
  <p>I am calling the routine in this way:</p>
  
  <pre><code>r_row, p_value = scipy.stats.pearsonr(array1, array2)
  </code></pre>
  
  <p>The value of <code>r_row</code> is always 1.0. What am I doing wrong?</p>