title: how to compare two columns with R
body: <p>I have a data frame and i'am tryng to compare two columns with this command :</p>
  
  <pre><code>table_NDCG=table_NDCG%&gt;%group_by(requete)%&gt;%mutate(comparaison=ifelse(url_cliquee.x==url_cliquee.y,TRUE,FALSE))
  </code></pre>
  
  <p>and this erros appears :</p>
  
  <blockquote>
    <p>Error in Ops.factor(url_cliquee.x, url_cliquee.y) :    level sets of
    factors are different</p>
  </blockquote>
  
  <pre><code>ifelse("http://intranet.com.intraorange#/{840f69af-91e4-44f5-a1b1-1940fb5edf54}/{962e8297-b167-4bf4-ad43-2360d64ca220}/{5f7cc0e2-6b03-4a92-b05b-813a0f5446eb}/3360/[http:||intranet.com.intraorange|fr|Pages|vifSR_06022019.aspx]   "=="    http://intranet-obs.com.ftgroup/obs/spip.php?article8070",TRUE,FALSE)
  </code></pre>
  
  <p>This is a real exemple with my data :
  sorry i can't post more there are confidential informations</p>
  
  <pre><code>&gt; ifelse("http://intranet.com.intraorange#/{840f69af-91e4-44f5-a1b1-1940fb5edf54}/{962e8297-b167-4bf4-ad43-2360d64ca220}/{5f7cc0e2-6b03-4a92-b05b-813a0f5446eb}/3360/[http:||intranet.com.intraorange|fr|Pages|vifSR_06022019.aspx] "=="    http://intranet-obs.com.ftgroup/obs/spip.php?article8070",TRUE,FALSE)
  [1] FALSE
  </code></pre>