title: ggplot xlab number sequence in R
body: <p>I'm using ggplot package in R to plot a simple point graph with the "Lecture" number on the xlab and the "music week" on the ylab.</p>
  
  <p>Here is the simple dataset I'm trying to plot:</p>
  
  <p><img src="https://i.stack.imgur.com/PrO6S.jpg" alt="Dataset - Music2"></p>
  
  <p>Here is the code I used:</p>
  
  <pre><code>ggplot(music2, aes(Lecture, Music)) + geom_point() + xlab("Lecture") +     ylab("Music Week")
  </code></pre>
  
  <p>Here is the plot I get:</p>
  
  <p><img src="https://i.stack.imgur.com/XEIzT.png" alt="point plot of dataset-music2"></p>
  
  <p>As showed above in the plot, the xlab of the plot doesn't go in the sequence of the numbers as in the dataset. Number 11 and 12 jump in between 1 and 2, instead of staying behind 10.</p>
  
  <p>How can I change the sequence into its natural order?</p>