title: Error: Can't subset columns that don't exist
body: <p>I'm trying to do a mixed anova with 1 between- and 3 within-subjects factors.</p>
  <p>My data looks like the following:</p>
  <pre><code>&gt; head(rt_dat_allconds)
  # A tibble: 6 x 6
  # Groups:   participant, search_difficulty, cue_validity [3]
    participant search_difficulty cue_validity cue_colour     mrt  cond
          &lt;dbl&gt; &lt;fct&gt;             &lt;fct&gt;        &lt;fct&gt;        &lt;dbl&gt; &lt;dbl&gt;
  1         642 difficult         FALSE        Match (Colo… 1.08      1
  2         642 difficult         FALSE        Mismatch (O… 1.00      1
  3         642 difficult         TRUE         Match (Colo… 0.961     1
  4         642 difficult         TRUE         Mismatch (O… 0.978     1
  5         642 easy              FALSE        Match (Colo… 0.945     1
  6         642 easy              FALSE        Mismatch (O… 0.885     1
  </code></pre>
  <p>I'm trying to run these lines of code for my anova:</p>
  <pre><code>res.aov &lt;- anova_test(data=rt_dat_allconds, dv=mrt, wid=participant, between=cond, within=c(search_difficulty, cue_validity, cue_colour))
  get_anova_table(res.aov)
  </code></pre>
  <p>However, when I run the line that begins with 'res.aov' I get the following error:</p>
  <p>&quot;Error: Can't subset columns that don't exist.
  x The columns <code>participant</code>, <code>search_difficulty</code>, and <code>cue_validity</code> don't exist.&quot;</p>
  <p>I'm not sure why it can't identify the columns. I can use those column names to do a variety of dplyr functions like group_by etc.</p>
  <p>Any ideas would be great. Thanks!</p>