hexfacet.r

library(gridExtra)
library(grid)
library(ggplot2)

xy <- polygon_regular(6)[-1,]*2

pl <- replicate(6, ggplot() + coord_polar() + theme_grey(), simplify = FALSE)

gs <- do.call(gList, lapply(1:6, function(id) grobTree(ggplotGrob(pl[[id]]), vp=letters[id])))
# gs <- do.call(gList, lapply(1:6, function(id) rectGrob(width=unit(2,"mm"), height=unit(2,"mm"), gp=gpar(fill=id), vp=letters[id])))
midpage <- unit(0.5,"npc")
xl <- lapply(xy[,1], function(x) unit(x, "cm") + midpage)
yl <- lapply(xy[,2], function(x) unit(x, "cm") + midpage)
vps <- do.call(vpList, mapply(viewport, x=xl, y=yl, name = letters[1:6], 
                              MoreArgs = list(width=unit(2,"cm"), height=unit(2,"cm")), 
                              SIMPLIFY = FALSE))
gl <- gTree(children = gs, 
            childrenvp = vps)


grid.newpage()
grid.draw(gl)