title: Two geom_line and geom_point on same plot
body: <p>I have a data frame <code>df</code> which looks like this</p>
  
  <pre><code>    &gt; dput(head(df))
      structure(list(Percent = c(1, 2, 3, 4, 5), Test = c(4, 2, 3, 
      5, 2), Train = c(10, 12, 10, 13, 15)), .Names = c("Percent", 
      "Test", "Train"), row.names = c(NA, 5L), class = "data.frame")
  </code></pre>
  
  <p>Looks like this</p>
  
  <pre><code>Percent    Test    Train
  1          4       10
  2          2       12
  3          3       10
  4          5       13
  5          2       15
  </code></pre>
  
  <p>How can I plot <code>Test</code> and <code>Train</code> into a two lines with <code>ggplot</code> ? </p>
  
  <p>I've got something like this right now</p>
  
  <pre><code>ggplot(dfk, aes(x = Percent, y = Test)) + geom_point() + 
    geom_line() 
  </code></pre>
  
  <p>I also want to add <code>Train</code> points and line connected onto the plot and have them a different color with labels in a legend. I am not sure how to do this.</p>
  
  <p><a href="https://i.stack.imgur.com/HubxP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HubxP.png" alt="enter image description here"></a></p>