title: Is there a way to remove the border of the legend in ggplot2?
body: <p>I'm using qplot to plot a function and I want to position the legend within the plot. I've used </p>
  
  <pre><code>opts( legend.position = c(0.7,0.7) )
  </code></pre>
  
  <p>to move the legend where I want it to be.</p>
  
  <p>However there is a white border around the legend and that shows up on the gray background. </p>
  
  <p>For example:</p>
  
  <pre><code>library(ggplot2)
  x = c(1:20)
  y = c(1:20)
  
  p &lt;- qplot(x,y, color = "blue")
  
  p &lt;- p + scale_colour_identity("Example", breaks=c("blue"), labels=c("dots"))
  
  p &lt;- p + opts(legend.position = c(0.6, 0.4))
  
  print(p)
  </code></pre>
  
  <p>I would like to know how to remove this border from the legend. Thank you.</p>