title: Attempting to plot simple raster map but coordinate labels showing as 1s
body: <p>I'm trying to run the below code to produce a simple map with data overlayed but I keep having the same issue with the gridline labels, they should read standard long/lat coords but all I'm getting are 1s.</p>
  <p>Everything works until the bottom line of code but I've put all in incase there's anything earlier that might be causing the issue.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>tern&lt;-read.table("terndatanumbers2.txt",header=TRUE)
  tern.coords &lt;- SpatialPoints(data.frame(x=terns$long,y = terns$lat))
  plot(tern.coords, pch = 15, cex = 0.5, col = "blue")
  
  world &lt;- rworldmap::getMap(resolution = "high")
  e &lt;- raster::extent(-32,-25,36,40)
  azores &lt;- as(raster::crop(world, e), "SpatialPolygons")
  raster::crs(tern.coords) &lt;- raster::crs(azores)
  plot(azores, col = "gray", xlim = c(-32,-25), ylim = c(36, 40))
  plot(tern.coords, pch = 15, cex = 0.5, col = "blue",xlim = c(-32,-25), ylim = c(36, 40), add = T)
  plot(gridlines(azores), lty = 3, col = "gray", lwd = 0.5,xlim = c(-32,-25), ylim = c(36, 40), add = T)
  text(labels(gridlines(azores)))</code></pre>
  </div>
  </div>
  </p>
  <p><a href="https://i.stack.imgur.com/N3yCk.png" rel="nofollow noreferrer">plot produced</a></p>
  <p>Any help on this would be appreciated. Thanks.</p>