title: Is there any R function to fulfill NA values with other values in the same column?
body: <p>I want to convert the next dataframe:</p>
  <pre><code>&gt;df1 
  
          A   B   C
      1   NA  NA  NA
      2   NA  NA  NA
      3   NA  NA  77
      4   NA  67  41
      5   20  28  65
      6   19  39  72
  </code></pre>
  <p>into:</p>
  <pre><code>&gt;df1 
  
          A   B   C
      1   20  67  77
      2   19  28  41
      3   NA  39  65
      4   NA  NA  72
      5   NA  NA  NA
      6   NA  NA  NA
  </code></pre>
  <p>In other words, I would like to impute the NA values with the other values in the same column.</p>