title: vtk python icp how to get transform matrix
body: <p>It seems that the answer to my question is pretty obvious, but unfortunately I could not figure it out, please help me!</p>
  
  <p>I am trying to use the vtk library to obtain the icp transform in python.</p>
  
  <p>I am running this code here:
  <a href="http://www.vtk.org/Wiki/VTK/Examples/Python/IterativeClosestPoints" rel="nofollow">http://www.vtk.org/Wiki/VTK/Examples/Python/IterativeClosestPoints</a></p>
  
  <p>and then </p>
  
  <pre><code>print icp.GetLandmarkTransform()
  </code></pre>
  
  <p>The result displays the transformation matrix among other things.</p>
  
  <p>... </p>
  
  <pre><code>Elements:
  -&gt;        1 4.76975e-10 0 -7.79873e-10 
  -&gt;       -4.76975e-10 1 -0 1.58991e-10 
  -&gt;       -0 0 1 0 
  -&gt;        0 0 0 1 
  Mode: RigidBody
  </code></pre>
  
  <p>...</p>
  
  <p>How do I extract the transformation matrix in a numpy array?
  I just need the transform for a 2D data set. Is there a simpler way to do it?</p>
  
  <p>Thank you in advance!</p>