title: Matplotlib: data not showing on the two sides in heatmap using x, y, z values stored in lists
body: <p>I am trying to generate a heatmap using Matplotlib for the first time. I have values (z) for each x, y cells. Thanks to <a href="https://gist.github.com/teechap/9c066a9ab054cc322877" rel="nofollow noreferrer">this page</a>, I think I am close to getting what I want but my plot does not show all the data. It is missing the 5th column and 5th row. Am I missing something?</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  
  # x, y data
  x = [1, 2, 3, 4, 5]
  y = [1, 2, 3, 4, 5]
  
  z = [
      [100, 500, 10, 50, 100],
      [200, 600, 100, 600, 200],
      [300, 700, 50, 700, 300],
      [200, 600, 100, 600, 200],
      [600, 200, 10, 50, 600]
      ]
  
  x, y = np.meshgrid(x, y)
  
  z = np.array(z)
  plt.pcolormesh(x, y, z, cmap = 'Blues')
  plt.colorbar()
  plt.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/WRKv7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WRKv7.png" alt="enter image description here"></a></p>