jwdink/egg

(fragile) extensions for ggplot2

egg

Misc. doomed tricks for ggplot2.

Exposing ggplot2 layouts

p1 <- qplot(mpg, wt, data=mtcars, colour=cyl)
p2 <- qplot(mpg, data = mtcars) + ggtitle("title")
p3 <- qplot(mpg, data = mtcars, geom = "dotplot")
p4 <- p1 + facet_wrap(~carb, nrow=1) + theme(legend.position="none") +
  ggtitle("facetted plot")
pl <- lapply(list(p1,p2, p3, p4), expose_layout, FALSE, FALSE)
grid.arrange(grobs=pl, widths=c(1.2,1,1),
             layout_matrix = rbind(c(1, 2, 3),
                                   c(4, 4, 4)))

Setting panel size

p1 <- qplot(mpg, wt, data=mtcars, colour=cyl)
p2 <- p1 + facet_wrap(~carb, nrow=1) 
grid.arrange(grobs=lapply(list(p1,p2), set_panel_size, 
                          width = unit(2,"cm"), height = unit(1, "in")))

Aligning complex ggplots

p1 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
  geom_point() 

p2 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
  geom_point() + facet_wrap( ~ cyl, ncol=2, scales = "free") +
  guides(colour="none") +
  theme()

p3 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
  geom_point() + facet_grid(. ~ cyl, scales = "free")

g1 <- ggplotGrob(p1);
g2 <- ggplotGrob(p2);
g3 <- ggplotGrob(p3);
fg1 <- gtable_frame(g1, debug=TRUE)
fg2 <- gtable_frame(g2, debug=TRUE)
fg12 <- gtable_frame(rbind(fg1,fg2), width=unit(2,"null"), height=unit(1,"null"))
fg3 <- gtable_frame(g3, width=unit(1,"null"), height=unit(1,"null"), debug=TRUE)
grid.newpage()
combined <- cbind(fg12, fg3)
grid.draw(combined)

Arranging and aligning multiple plots

This is a convenience function based on the above, more useful than grid.arrange for the special case of ggplots as it aligns the plot panels,

p1 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
geom_point() 
p2 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
geom_point() + facet_wrap( ~ cyl, ncol=2, scales = "free") +
guides(colour="none") +
theme()

ggarrange(p1, p2, widths = 1:2)