Specify position of geom_text by keywords like “top”, “bottom”, “left”, “right”, “center”

Question

I wish to position text in a ggplot without specifying x and y positions, but instead using keywords, like e.g. in graphics::leg

Answer 1

In ggpmisc::geom_text_npc the x and y positions are given in npc units (0-1). However, the positions can also be specified as "words":

d = data.frame(x = rep(c("left", "center", "right"), each = 3),
               y = rep(c("bottom", "middle", "top"), 3))
d$lab = with(d, paste0(x, "-", y))
d
#        x      y           lab
# 1   left bottom   left-bottom
# 2   left middle   left-middle
# 3   left    top      left-top
# 4 center bottom center-bottom
# 5 center middle center-middle
# 6 center    top    center-top
# 7  right bottom  right-bottom
# 8  right middle  right-middle
# 9  right    top     right-top

ggplot(d) +
  geom_text_npc(aes(npcx = x.chr, npcy = y.chr, label = lab))