title: How to zoom on a quiver plot without loading the cut part, and with arrows of good length? (Python)
body: <p>I plot a quiver with matplotlib.pyplot, and would like to:</p>
  <ol>
  <li>Zoom around a chosen coordinate (and in a chosen range around this coordinate).</li>
  <li>Not have to load all the plot and then set an xlim/ylim. It means that I can cut the plot before and it will not take a lot of time compared to if I need to compute the whole uncut plot (which is what is done for now in the code below).</li>
  <li>Be able to zoom again if needed in the interactive plot (I use nbagg).</li>
  <li>Get some arrows that are sufficiently big (i.e. not just the small heads!) in the window that is plotted.</li>
  </ol>
  <p><strong>Code using xlim and ylim:</strong></p>
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  
  ext = 4
  points = 1000
  target = (2,2)
  around_target = 0.5
  
  x,y = np.meshgrid(np.linspace(-ext,ext,points),np.linspace(-ext,ext,points))
  
  u = x
  v = y
  
  plt.figure(figsize=(6,6))
  plt.quiver(x,y,u,v,angles='xy', scale_units='xy')
  plt.xlim(target[0]-around_target = 0.5,target[0]+around_target = 0.5)
  plt.ylim(target[1]-around_target = 0.5,target[1]+around_target = 0.5)
  
  plt.show()
  </code></pre>