title: How to remove filled area on SE when plot "geom_smooth" in ggplot2?
body: <p>I would like to plot a <code>geom_smooth()</code> in ggplot2 without filled <code>se</code>, but only the two edges of the <strong>se</strong>.</p>
  
  <p>I have tried to use the code <code>geom_smooth(method="loess", se=T, fill=NA)</code>, but it doesn't give what I expected.</p>
  
  <pre><code>    ggplot(mtcars, aes(x=wt, y=mpg)) +
        geom_point(size=2)+
        geom_smooth(method = "loess", se=T)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/4saSd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4saSd.png" alt="Something like the figure shows"></a></p>