title: Plotting only stat_smooth without original ggplot2 data
body: <p>I plot data with ggplot, and I wanted to see the smoothed lines using stat_smooth.<br>
  But now I would like to only plot the smoothed lines (somehow extract it), without the original ggplot.<br>
  Do you think it's possible?</p>
  
  <p>Here is my code :</p>
  
  <pre><code>Graph &lt;- ggplot(data=Forecasttemp, aes(x=Price.date, y=Price, colour=Group)) + geom_line() + scale_colour_hue(guide = "none")
  Graph &lt;- Graph + stat_smooth(se = FALSE,  aes(fill = Group)) + scale_colour_hue(guide = "none")
  </code></pre>