title: Change the thousands separator in a ggplot
body: <p>While making a bar plot with ggplot I run into troubles getting the preferred thousands separator. I would like thousands to be separated by a dot instead of a comma. Like this it gives no separator: </p>
  
  <pre><code>require(ggplot2)
  require(scales) 
  options(scipen=10)
  D = data.frame(x=c(1,2),y=c(1000001,500000))
  p = ggplot(D,aes(x,y)) + geom_bar(stat="identity") 
  p
  </code></pre>
  
  <p>and like this it gives a comma:</p>
  
  <pre><code>p + scale_y_continuous(labels=comma)
  </code></pre>
  
  <p>How do you get a dot as thousands separator? I can't find documentation on which types of other labels exist besides some examples on <a href="http://docs.ggplot2.org/0.9.3.1/scale_continuous.html" rel="noreferrer">http://docs.ggplot2.org/0.9.3.1/scale_continuous.html</a>. </p>
  
  <p>Thanks in advance,</p>
  
  <p>Forza</p>