title: ggpubR "Can only handle data with groups that are plotted on the x-axis"
body: <p>When running the following with ggpubr, i receive the error </p>
  
  <blockquote>
    <p>"Error in f(...) : Can only handle data with groups that are plotted on the x-axis"</p>
  </blockquote>
  
  <pre><code>my_comparisons &lt;- list( c('A_1538_C', '1594delete12') )
  ggplot(dt) +
  geom_jitter(width = 0.1, height = 0, aes(
      x=reorder(allele,mu_normal),
      y=mu_normal)) + 
    theme_bw() +
    theme(axis.text.x = element_text(angle =60, vjust = 1, hjust=1)) +
    stat_compare_means(comparisons = my_comparisons, method = "t.test")
  </code></pre>
  
  <p><code>stat_compare_means</code> is functioning in another plot of mine, and this is not the issue others have run into when x is an interaction of terms. (details on that issue here: <a href="https://github.com/const-ae/ggsignif/issues/16" rel="nofollow noreferrer">https://github.com/const-ae/ggsignif/issues/16</a> )</p>
  
  <p>the value of </p>
  
  <pre><code>unique(dt$allele)
  </code></pre>
  
  <p>is </p>
  
  <pre><code>[1] A_1714_C     C_1721_A     G_1546_T     A_443_T      C_1535_T     A_1538_C    
  [7] 1594delete12 rpoB_1547A.G rpoB_1534T.C WT           rpsL_128A.G  rpsL_263A.G 
  [13] gyrA_248C_T 
  15 Levels: 1594delete12 A_1538_C A_1714_C A_443_T blank C_1535_T ... rpsL_263A.G
  </code></pre>
  
  <p>so it seems like <code>my_comparisons</code> is a set of existing terms? (I'd like to expand to more comparisons when it's working)</p>