title: How to center a plotted image?
body: <p>I didn't post the whole code because most of it isn't relevant. I just need help with centering the image. </p>
  
  <pre><code>ra_new2=cat['ra'][z&amp;lmass&amp;ra&amp;dec][i]
  dec_new2=cat['dec'][z&amp;lmass&amp;ra&amp;dec][i]
  target_pixel_x = ((ra_new2-ra_ref)/(pixel_size_x))+reference_pixel_x     
  target_pixel_y = ((dec_new2-dec_ref)/(pixel_size_y))+reference_pixel_y    
  fig = plt.figure(figsize=(5.,5.))
  galaxy=plt.imshow(img[target_pixel_x-200:target_pixel_x+200, target_pixel_y- 
  200:target_pixel_y+200], vmin=-0.01, vmax=0.1, cmap='Greys')
  plt.show()
  </code></pre>
  
  <p>The plt.imshow is what I'm trying to center. It plots correctly and all, but the plot is at the bottom left. How do I put this in the middle of the graph window? I need this so that I can adjust the parameters of the zoom. </p>