title: How to plot plot pairwise comparisons in ggplot2 (only sample statistics)
body: <p>I would like to make a bar graph that shows the means, the standard error of the means, and significant pairwise comparisons.</p>
  
  <p>Something similar to this:</p>
  
  <p><a href="https://i.stack.imgur.com/wLQio.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wLQio.jpg" alt="enter image description here"></a></p>
  
  <p>The data I have are only the means and standard error of the means.</p>
  
  <pre><code>group   x   mean   se of mean
  a       1   3.650   0.092
  a       2   4.232   0.081
  a       3   3.653   0.068
  a       4   3.871   0.13
  b       1   3.984   0.07
  b       2   4.150   0.073
  b       3   4.058   0.054
  b       4   4.010   0.132
  c       1   2.915   0.1
  c       2   3.475   0.1
  c       3   3.246   0.086
  c       4   3.069   0.16
  </code></pre>
  
  <p>Any ideas?</p>