title: How to remove duplicated row depending on two different columns in r?
body: <p>I want to delete all the duplicated rows from my data.frame only if their values on another column is different.</p>
  
  <p>Let's say I have a data.frame like this :</p>
  
  <pre><code>Column1 Column2 Column3
  A       -       10
  A       -       13
  A       -       15
  B       -       18
  B       -       18
  B       -       23
  </code></pre>
  
  <p>The result should be :</p>
  
  <pre><code>Column1 Column2 Column3
  A       -       10
  B       -       18
  B       -       18
  </code></pre>