I have several faceted histograms (obtained with the command below) which are nicely plotted one under the other. I would like to increase the spacing between them, however, they are tight.

I looked at the doc but didn't find a parameter for this. 

qplot (Happiness.Level, Number.of.Answers, data=mydata, geom="histogram") + facet_grid (Location ~ .)
r ggplot2
Edit
Report