title: Plotting some values to a polar graph in matplotlib
body: <p>I want to plot some values representing visible satellites into a polar graph with Python and matplotlib. I have written some code following a matplotlib example, and the polar chart is represented, but given points are not plotted:</p>
  
  <pre><code>import matplotlib
  from matplotlib.pyplot import figure, show, rc, grid
  from math import pi
  
  # radar green, solid grid lines
  rc('grid', color='#316931', linewidth=1, linestyle='-')
  rc('xtick', labelsize=15)
  rc('ytick', labelsize=15)
  
  # force square figure and square axes looks better for polar, IMO
  width, height = matplotlib.rcParams['figure.figsize']
  size = min(width, height)
  # make a square figure
  fig = figure(figsize=(size, size))
  ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True, axisbg='#d5de9c')
  
  # Satellite info [PRN, E, Az, Ss, Used (1 yes, 0 no)]
  sat = [ [1, 62, 255, 46, 1],
          [14, 62, 26, 46, 1],
          [31, 42, 158, 36, 1],
          [22, 40, 76, 50, 1],
          [11, 29, 308, 0, 0],
          [19, 26, 243, 36, 1],
          [3, 13, 217, 0, 0],
          [18, 10, 93, 0, 0],
          [20, 6, 291, 0, 0],
          [5, 1, 72, 0, 0],
          [122, 43, 216, 0, 0],
          [135, 47, 203, 43, 0] ]
  
  for index in (0, len(sat)-1):
      if(sat[index][4]&gt;0):
          ax.plot(sat[index][2], sat[index][1], color='green', marker='s', markersize=12)
      else:
          ax.plot(sat[index][2], sat[index][1], color='gray', marker='s', markersize=12)
  
  ax.set_rmax(2.0)
  grid(True)
  
  ax.set_title("Visible satellites", fontsize=20)
  show()
  </code></pre>
  
  <p>What am I doing wrong?</p>