title: Modify Text Legend ggplot2
body: <p>I would like to modify the legend in ggplot2 using the text geom.  Example is shown below.  I want to change the a's to points (circles) and instead of 1, 2, 3 use custom names such as low, medium, high.  Any suggestions would be greatly appreciated.</p>
  
  <p>Example Data:</p>
  
  <pre><code>   x  y Freq colors
  1 -2 32    2      1
  2 -2 36    1      1
  3 -2 37    1      1
  4 -2 40    2      1
  5 -1 32    2      1
  6  0 29    2      1
  </code></pre>
  
  <p>Code:</p>
  
  <pre><code>  fit=ggplot(a1,aes(x,y,color=factor(colors)),col=colors)+
      geom_text(aes(label=Freq),size=5)+
      theme_bw()+
      opts(legend.position='top',
           legend.title=theme_blank(),
           legend.key=theme_rect(fill="white",colour="white"))
    print(fit)
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/hzgqZ.png" alt="enter image description here"></p>