title: Getting Median of a Column where value of another Column is 1 in R
body: <p>Ok so I have a csv file similar to this structure</p>
  
  <pre><code>hashID,value,flag
  
  98fafd,   35,   1
  
  fh56w2,   25,   0
  
  ggjeas,   55,   1
  
  adfh5d,   45,   0
  </code></pre>
  
  <p>Basically what I want to do is get the median of the value column but only include rows where <code>flag==1</code> in the calculation.</p>
  
  <p>Is this even possible in R? I've searched around and haven't found anything like this.</p>