我这里有一个模拟数据集，我想在x轴上以特定的间隔引入更大的间隙。
我希望这些差距更大，特别是日间组之间。
在这种情况下，在前2组之后，然后在后2组之后，然后在接下来的3组之后，差距会更大，依此类推......
以下是我当前的输出：

下面是我的代码：

library("ggplot2")
library("grid")
library("dplyr")

df <- data.frame(
  day = c(rep(11, 6), rep(12, 6), rep(23, 9), rep(31, 9), rep(47, 9)),
  hz = c(rep(1, 3), rep(2, 3), rep(1, 3), rep(2, 3), rep(1, 3), rep(2, 3), rep(4, 3) , rep(1, 3), rep(2, 3), rep(4, 3), rep(1, 3), rep(2, 3), rep(4, 3)),
  ft = c(38,42,45,28,30,45,38,41,45,25,30,45,45,43,50,30,28,48,30,33,40,45,41,47,38,35,43,30,32,50,46,40,50,38,30,40,30,28,40),
  sp = c(rep(c("Ctrl", "Absrc", "Ab42"), 13))
)

se <- function(a) sd(a)/sqrt(length(a))

g1 <- ggplot(df, aes(x=interaction(hz, day), y=ft, group=desc(sp), fill=sp)) +
  geom_bar(position=position_dodge(), stat="identity") +
  geom_errorbar(aes(ymax=ft+se(ft), ymin=ft-se(ft)), position=position_dodge(0.9), width=0.5) +
  coord_cartesian(ylim=c(0, 60)) +
  annotate("text", x=c(1.5, 3.5, 6, 9, 12), y=-6, label=c("day 11", "day 12", "day 23", "day 31", "day 47")) +
  annotate("text", x=1:13, y=-3, label=c(rep(c("1 hz", "2hz"), 2), rep(c("1 hz", "2 hz", "4hz"), 3))) +
  theme_classic() + 
  theme(plot.margin=unit(c(1,1,4,1), "lines"),
        axis.title.x= element_blank(),
        axis.text.x=element_blank()) + 
  scale_fill_discrete(breaks=c("Ctrl", "Absrc", "Ab42")) + 
  scale_fill_grey() + 
  scale_y_continuous(expand=c(0,0))

g2 <- ggplot_gtable(ggplot_build(g1))
g2$layout$clip[g2$layout$name == "panel"] <- "off"
grid.draw(g2)

ggsave(file="graph.svg", plot=g2)