title: scipy equivalent for MATLAB spy
body: <p>I have been porting code for an isomap algorithm from MATLAB to Python. I am trying to visualize the sparsity pattern using the spy function.</p>
  
  <p>MATLAB command:</p>
  
  <pre><code>spy(sparse(A));
  drawnow;
  </code></pre>
  
  <p>Python command:</p>
  
  <pre><code>matplotlib.pyplot.spy(scipy.sparse.csr_matrix(A))
  plt.show()
  </code></pre>
  
  <p>I am not able to reproduce the MATLAB result in Python using the above command. Using the command with only A in non-sparse format gives quite similar result to MATLAB. But it's taking quite long (A being 2000-by-2000). What would be the MATLAB equivalent of a sparse function for scipy?</p>