问题 I have a plot like this below: library(ggplot2) library(ggh4x) # remotes::install_github("teunbrand/ggh4x") df1 <- data.frame(x = rep(1:12, times=4, each=1), y = rep((1:12)^2, times=4, each=1), Variable1 = rep(c("A","B"), times=1, each=24), Variable2 = rep(c("C","D"), times=4, each=12)) g<-ggplot(df1, aes(x=x, y=y)) + geom_point(size=1.5) + theme(strip.background = element_rect(colour = "black", fill = "white", size = 1.5, linetype = "solid"), axis.title.x =element_text(margin = margin(t = 2,