title: How allclose() works?
body: <p>What is the difference between relative tolerance (<em>rtol</em>) and absolute tolerance (<em>atol</em>) in <em>allclose</em>. Somebody please explain the meaning of the following. </p>
  
  <pre><code>np.allclose(center_var,center_a,rtol=1e-02, atol=1e-03)
  </code></pre>