title: issue with including a dplyr::filter in a function
body: <p>I am having trouble with creating a function that includes a <code>filter()</code> function. </p>
  <p>I keep getting an error (shown below) with this function: </p>
  <pre><code>plot &lt;- function(df, group, varx, vary) {
    df %&gt;% 
      filter(PC == group) %&gt;%
      ggplot(aes(x = reorder(get(varx), get(vary)), y = get(vary))) + 
      geom_col() 
  
  } 
  </code></pre>
  <blockquote>
  <pre><code>Error in UseMethod(&quot;filter&quot;) : 
    no applicable method for 'filter' applied to an object of class &quot;character&quot;
  </code></pre>
  </blockquote>
  <p>Anyone have an explanation/solution? Thanks! </p>