title: Applying revgeocode to a list of longitude-latitude coordinates
body: <p>I'm trying to get the Zip codes of a (long) list of Longitude Latitude coordinates by using the revgeodcode function in the ggmap library.</p>
  
  <p>My question &amp; data are the same as here: <a href="https://stackoverflow.com/questions/17505147/using-revgeocode-function-in-a-for-loop-help-required/17505224#17505224">Using revgeocode function in a FOR loop. Help required</a> but the accepted answer does not work for me.</p>
  
  <p>My data (.csv):</p>
  
  <pre><code>ID,      Longitude,      Latitude
  311175,  41.298437,      -72.929179
  292058,  41.936943,      -87.669838
  12979,   37.580956,      -77.471439
  </code></pre>
  
  <p>I follow the same steps:</p>
  
  <pre><code>data &lt;- read.csv(file.choose())
  dset &lt;- as.data.frame(data[,2:3])
  location = dset
  locaddr &lt;- lapply(seq(nrow(location)), function(i){
                 revgeocode(location[i,],
                 output = c("address"),
                 messaging = FALSE,
                 sensor = FALSE,
                 override_limit = FALSE)
                 })
  </code></pre>
  
  <p>... and get the error message: "Error: is.numeric(location) &amp;&amp; length(location) == 2 is not TRUE"
  Specifically, is.numeric(location) is FALSE, which seems strange because I can multiply by 2 and get the expected answer.</p>
  
  <p>Any help would be appreciated.</p>