cowplot package
https://cran.r-project.org/web/packages/cowplot/vignettes/introduction.html
a simple add-on to ggplot2
Plot design
provide a publication-ready theme for ggplot2
Arranging graphs into a grid
plot_grid(plot.mpg, NULL, NULL, plot.diamonds, labels = c(“A”, “B”, “C”, “D”), ncol = 2)
Generic plot annotations
ggdraw(plot.mpg) +
draw_plot_label("A", size = 14) +
draw_label("DRAFT!", angle = 45, size = 80, alpha = .2)
