title: ggplot geom_line on top of geom_bar
body: <p>I'm looking to simply display in one plot the production(geom_line) and the import(geom_bar) of wheat over years with data pulled from faostat. So basically on the x-axis = year, on the y-axis = production, and on the final axis = import. Adding to that I would like to have the bars split by the country for import since there is more import from a certain country, but I don't wish to display all of them, only the top 3 and the rest should be in a new category &quot;other&quot;.</p>
  <p>I'm quite bad with the code in R but once I have the foundation I can figure out how to adjust the looks of it just need to figure out how to start.</p>
  <p>Here I'm providing a simplified dataset, as described, in the bar plot I want to show only the 3 highest values and have the rest combined into a new category &quot;other&quot;. And a geom_line should be displayed on top of that with a separate axis on the right side, for some reason the geom_line is not working for me.</p>
  <pre><code>import &lt;- data.frame(country = c(&quot;USA&quot;, &quot;USA&quot;, &quot;EU&quot;, &quot;NZ&quot;, &quot;EU&quot;, &quot;Bulgaria&quot;, &quot;Romania&quot;, &quot;Serbia&quot;),
                           date = c(&quot;1991&quot;, &quot;1992&quot;, &quot;1994&quot;, &quot;1995&quot;, &quot;1991&quot;, &quot;1991&quot;, &quot;1991&quot;, &quot;1991&quot;),
                           value = c(1000, 500, 2000, 1500, 1000, 100, 500, 500))
  
  production &lt;- data.frame(date = c(&quot;1991&quot;, &quot;1992&quot;, &quot;1994&quot;, &quot;1995&quot;, &quot;1995&quot;),
                         value = c(50, 45, 40, 39, 38))
  
  ggplot(data = import, mapping = aes(x=date, y=value, fill=country)) +
    geom_col()
  
  ggplot(data = production, aes(x=date, y=value)) +
    geom_line()
  </code></pre>
  <p>Any help or guidance in the right direction will be appreciated.
  Thank you in advance! Love this community always great with the help &lt;3</p>