title: dplyr filter statement not in expression from a data.frame
body: <p>I would like to use not in statement with a data.frame in dplyr but it is not working. I would like to exclude values from a data.frame since I do have huge week numbers. Below is an example </p>
  
  <pre><code>df1 = data.frame(week=c(1,2,3,4,5,6),sales=c(10,24,23,54,65,45))
  week_e=data.frame(week=c(2,5)) 
  </code></pre>
  
  <p>so I would like to exclude weeks in week_e data frame from df1 and below is code
  and it is not working. Please help! Thank you.</p>
  
  <pre><code>       df1  %&gt;%
         filter(!week %in% week_e)  
  
         week sales
     1    1    10
     2    2    24
     3    3    23
     4    4    54
     5    5    65
     6    6    45
  </code></pre>