Spreading out facetted plots (R)

Question

Is there a way to spread facetted plots apart in ggplot2? As you can see in the picture (the bottom section of my plot), the x-axes are overlapping a bit at the ends of each plot, obscuring the years. I'd like to move them apart. No matter how much I increase the width when exporting, the values still overlap.

My code, if relevant:

  ggplot(filter(TotalsRegion, Source!="Total"), aes(x=Date, y=SourceSum, col=Source)) +
   geom_line(size=1) +
   facet_grid(.~Region)

Answer 1

Since you did not provide a reproducible example, we'll have to make one for you.

library(ggplot2)
library(grid)

data(mpg)
mpg$displ <- mpg$displ + 2000
p <- ggplot(mpg, aes(displ, cty))
p <- p + geom_point()
p <- p + facet_grid(. ~ cyl)
p

p <- p + theme(panel.margin.x=unit(20, "pt"))
p

This does not suffer from the overlap (can't do all the work for you) but hopefully it's clear what the panel margin settings do.