title: Plotting point on top of filled contour plot adds lots of blank space
body: <p>I have the following Python code which I am using to plot a filled contour plot:</p>
  
  <pre><code>  def plot_polar_contour(values, azimuths, zeniths):
    theta = np.radians(azimuths)
    zeniths = np.array(zeniths)
  
    values = np.array(values)
    values = values.reshape(len(azimuths), len(zeniths))
  
    r, theta = np.meshgrid(zeniths, np.radians(azimuths))
    fig, ax = subplots(subplot_kw=dict(projection='polar'))
    ax.set_theta_zero_location("N")
    ax.set_theta_direction(-1)
    cax = ax.contourf(theta, r, values, 30)
    autumn()
    cb = fig.colorbar(cax)
    cb.set_label("Pixel reflectance")
    show()
  </code></pre>
  
  <p>This gives me a plot like:</p>
  
  <p><img src="https://i.stack.imgur.com/F6dNn.png" alt="enter image description here"></p>
  
  <p>However, when I add the line <code>ax.plot(0, 30, 'p')</code> just before <code>show()</code> I get the following:</p>
  
  <p><img src="https://i.stack.imgur.com/9jP3y.png" alt="enter image description here"></p>
  
  <p>It seems that just adding that one point (which is well within the original axis range) screws up the axis range on the radius axis.</p>
  
  <p>Is this by design, or is this a bug? What would you suggest doing to fix it? Do I need to manually adjust the axis ranges, or is there a way to stop the extra plot command doing this?</p>