title: ggplot without the use of subset
body: <p>I'm using ggplot2 with the faceting option to plot several results of a data.frame.</p>
  
  <p>It's a data.frame with three factors :</p>
  
  <ul>
  <li>participant (N) with 6 levels;</li>
  <li>condition (C) with 6 levels;</li>
  <li>stimuli (S) with 10 conditions.</li>
  </ul>
  
  <p>I plot the results of one participants in one condition using the subset function and then I facet with ggplot. However, I was wondering if there was an easier solution in ggplot2?</p>
  
  <p>Thanks for any help, I'm currently learning R and ggplot2.</p>