title: Correcting aspect ratio of circle plot with matplotlib.patches
body: <p>I am using matplotlib.patches to generate a circle. However, the circle generated is not visually circular. It appears like an ellipse. It is probably due to some aspect ratio setting which I am not able to figure out with patches. How can I get a visually circular circle with matplotlib.patches module?</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  import matplotlib.path as mpath
  import matplotlib.lines as mlines
  import matplotlib.patches as mpatches
  from matplotlib.collections import PatchCollection
  
  fig, ax = plt.subplots()
  grid = np.mgrid[0.2:0.8:3j, 0.2:0.8:3j].reshape(2,-1).T
  
  patches = []
  
  circle1 = mpatches.Circle(grid[4], 0.25, linestyle='-.', fill=False)
  
  ax.add_patch(circle1)
  
  ax.grid(color='r', linestyle='-.', linewidth=1)
  
  # plt.subplots_adjust(left=0.1, bottom=0.1, right=0.5, top=0.5,
  #                 wspace=0.1, hspace=0.1)
  # plt.tight_layout()
  plt.show()
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/QY20C.png" width="400" /></p>