title: replacing specific values with NA using na_if
body: <p>My dataframe has few values as 9.969210e+36, I want to replace them with NA. It looks like</p>
  
  <pre><code># A tibble: 1,308 x 3
         IMD     CRU dts       
       &lt;dbl&gt;   &lt;dbl&gt; &lt;date&gt;    
   1 9.97e36 9.97e36 1901-01-01
   2 9.97e36 9.97e36 1902-01-01
   3 9.97e36 9.97e36 1903-01-01
   4 9.97e36 9.97e36 1904-01-01 
  </code></pre>
  
  <blockquote>
    <p>dput(head(df))</p>
  </blockquote>
  
  <pre><code>structure(list(IMD = c(9.96920996838687e+36, 9.96920996838687e+36, 
  9.96920996838687e+36, 9.96920996838687e+36, 9.96920996838687e+36, 
  9.96920996838687e+36), CRU = c(9.96920996838687e+36, 9.96920996838687e+36, 
  9.96920996838687e+36, 9.96920996838687e+36, 9.96920996838687e+36, 
  9.96920996838687e+36), dts = structure(c(-25202, -24837, -24472, 
  -24107, -23741, -23376), class = "Date")), class = c("tbl_df", 
  "tbl", "data.frame"), row.names = c(NA, -6L))
  </code></pre>
  
  <p>I followed <a href="https://stackoverflow.com/questions/49457877/r-replace-specific-value-contents-with-na">R - Replace specific value contents with NA</a> as</p>
  
  <pre><code>df %&gt;% mutate_at(vars(IMD, CRU), na_if, 9.969210e+36)
  df %&gt;% na_if(x=as.vector(df$IMD),y=9.97e36)
  </code></pre>
  
  <p>None of the above shows NA values and returns same old dataframe.
  Any help is appreciated </p>