title: Smoothing geom_path() with scale_y_reverse() and stat_smooth()
body: <p>My dataset:</p>
  
  <pre><code>reading,depth
  31055,0.0
  57635,0.5
  34268,1.0
  20926,1.5
  13507,2.0
  12944,2.5
  13002,3.0
  12892,3.5
  12610,4.0
  12158,4.5
  12004,5.0
  </code></pre>
  
  <p>I'm plotting an instrument reading as a function of below-ground depth. Because of what I'm visualizing, I want the axes to have a non-standard configuration, like this:</p>
  
  <pre><code>ggplot(data=f0101, aes(x=reading, y=depth)) + 
      theme_classic() + 
      scale_y_reverse() + 
      scale_x_continuous(position="top") + 
      geom_path()
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/YV8qX.png" alt="img1"></p>
  
  <p>This is perfect, except that I'd like the line smoothed, via stat_smooth() or similar. But, calling a smooth appears to throw off geom_path().</p>
  
  <pre><code>ggplot(data=f0101, aes(x=reading, y=depth)) + 
      theme_classic() + 
      scale_y_reverse() + 
      scale_x_continuous(position="top") + 
      geom_path() + 
      stat_smooth()
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/P7lyj.png" alt="img2"></p>
  
  <p>What can I do to get the smoothing effect of stat_smooth() while still plotting the data in an admittedly non-standard configuration?</p>
  
  <p>Thank you!</p>