title: can't delimit an autokrige in map using ggplot in r
body: <p>I am doing an interpolation with the kriging method in r. I want to add a map over it, but I don't want any space left. I am using the <code>automap</code> and <code>ggplot2</code> libraries and the raster method is <code>autoKrige</code>.</p>
  <pre><code># realization of the kriging method with the automap library
  coordinates(dato1) = ~ X+Y
  
  grad_ter_autokrig = autoKrige(GradTerm~1, dato1,)#diagrama de autokrige
  str(grad_ter_autokrig)
  
  #we convert the autokrige into a dataset to be read by ggplot
  ggplot_data = as.data.frame(grad_ter_autokrig$krige_output)
  str(ggplot_data)
  
  #we make the outline of the map
  contornokring&lt;-data.frame(x=df$long,y=df$lat)
  contornokring
  plot(contornokring)
  
  #We make the graph with raster its interpolation and with geom_polygon the polygon
  ggplot(df, aes(x=long,y=lat)) + 
    geom_raster(data=ggplot_data, aes(x = x1, y = x2, fill = var1.pred),inherit.aes = FALSE) +
    geom_polygon(data=df,aes(x=long,y=lat),fill=NA,
                 colour='black')
  </code></pre>
  <p><a href="https://i.stack.imgur.com/vXFjz.png" rel="nofollow noreferrer">This is the result of my code</a></p>