How to annotate some text in the blank space within a odd numbered faceted ggplot. Lets have a faceted ggplot with data as below with with 2 rows and 2 columns. So there is blank space in place of 2 row, 2nd column.
df<- data.frame(Ara = rep("XTX", each = 3),
Len = c(744, 750, 755),
Mon = c("Sep", "Oct","Nov"),
Value=c(11.224,10.15,4.23))
df
facetplot<-ggplot(df, aes(x=Value, y=Len, shape=Ara))+
geom_point(size=5.0)+
theme(legend.position = c(.7, .4), legend.direction="vertical")+
facet_wrap(~Mon,scales="free_x", nrow=2)
facetplot
Now i am trying to annotate some text in the space but could not ( as written in red in the image). I am looking for something similar to legend.position for annotated text. Do anyone has any idea on this.Or what would be the possible work around.
Thank you.
After you create your plot, simply use
print(facetplot)
grid.text("your text", x = 0.75, y = 0.25)
See ?grid.text for details on positioning. The default coordinate system is the entire screen device with (0,0) as the lower left and (1,1) as the upper right.
来源：https://stackoverflow.com/questions/29594348/how-to-position-annotate-text-in-the-blank-area-of-facet-ggplot