title: Drop rows when two columns aren't equal in R
body: <p>I have a data.frame which was the result of a merge of two separate data.frames, I have multiple columns but am concerned about Area.x and Area.y coming from both dataframes.</p>
  
  <p>In particular, I want to remove all the rows where the value in Area.x is different from the value in Area.y (Area is numeric).</p>
  
  <p>So I tried this, but it seems it doesn't work :</p>
  
  <pre><code>mergeTest[!(mergeTest$`Area.x` != mergeTest$`Area.y`),]
  </code></pre>
  
  <p>EDIT : Sorry, I found the problem, the guys who gave me the databases of 1 000 00 rows made the Area.x in numeric and the Area.y in chr. So the test just wasn't working</p>
  
  <p>Really sorry again</p>