title: How to invert the x or y axis
body: <p>I have a scatter plot graph with a bunch of random x, y coordinates. Currently the Y-Axis starts at 0 and goes up to the max value. I would like the Y-Axis to start at the max value and go up to 0.</p>
  
  <pre><code>points = [(10,5), (5,11), (24,13), (7,8)]    
  x_arr = []
  y_arr = []
  for x,y in points:
      x_arr.append(x)
      y_arr.append(y)
  plt.scatter(x_arr,y_arr)
  </code></pre>