title: Loop through each row in a data frame, extract values from raster and write csv files
body: <p>I have a data frame with a <code>Name</code>, <code>longitude</code> and <code>latitude</code> columns. I want a function that goes trough each row, extract the values from a raster stack and write csv files based on the <code>Name</code> column.</p>
  
  <pre><code>Name    Lon     Lat
  Name1   11.11   47.87
  Name2   150.1   -40.4
  Name3   -50.2   -3.5
  Name4   -100.3  49.8
  
  library(raster)
  s &lt;- stack(replicate(5, {raster(matrix(runif(2160*4320), 2160), 
           xmn=-180, xmx=180, ymn=-90, ymx=90)}))
  
  I can do that one by one:
  
  location &lt;- data.frame(11.11, 47.87)
  ex &lt;- extract(s, location)
  write.csv(ex, "Name1.csv")
  </code></pre>