title: Drawing random numbers returns only integers
body: <p>I am probably missing an important point on statistics or numpy/scipy.
  I want to generate random numbers with poissonian statistics, whose expected value is <code>a decimal less than 1</code>, e.g., <code>lambda = 0.6</code>.
  When I pythonize this:</p>
  
  <pre><code>&gt;&gt;&gt; from scipy.stats import poisson
  &gt;&gt;&gt; import numpy as np
  &gt;&gt;&gt; lambda = 0.6
  &gt;&gt;&gt; poisson.rvs(lambda, size=10)
  &gt;&gt;&gt; print r
  [2 2 0 0 0 2 1 0 0 2 ]
  </code></pre>
  
  <p>Trying</p>
  
  <pre><code>&gt;&gt;&gt; r = np.real(poisson.rvs(lambda, size=10))
  </code></pre>
  
  <p>Gives the same result.</p>
  
  <p>Why there are no decimals between 0 and 1 ?</p>