title: Ignore case while using duplicated
body: <p>I am using the duplicated function in R to remove the duplicate rows in my data frame.</p>
  
  <pre><code> df:
  
   Name Rank
    A    1
    a    1
    B    2
  
  
  df[!duplicated(df),]
  
   Name Rank
    A    1
    a    1
    B    2
  </code></pre>
  
  <p>The second row is same as the first, but doesn't get deleted just because it takes the case of the <strong>"A" and "a"</strong> in to consideration. What is the turn around this? Thanks.</p>