How to use empty space produced by facet_wrap?
You can use gtable to access the "empty cell" like so
library(gtable)pg <- ggplotGrob(p)qg <- ggplotGrob(q)pl <- gtable_filter(pg, 'panel', trim=F)$layoutpg <- gtable_add_grob(pg, qg, t=max(pl$t), l=max(pl$l))grid.newpage()grid.draw(pg)Edit: generic placement for n x m facets