如何将误差线定位在适当颜色的条的中心？
df1 <- data.frame(
supp = c("OJ","OJ","OJ","VC","VC","VC"),
dose = c(0.5,1,2,0.5,1,2),
len = c(13.23,22.7,26.06,7.98,16.77,26.14),
se = c(1.41,1.27,0.84,0.87,0.8,1.52)
)
df1$dose <- factor(df1$dose)
ggplot(df1, aes(x=dose, y=len, fill=supp)) +
geom_bar(stat="identity", position=position_dodge()) +
scale_fill_manual(name = "", values = c("deepskyblue1", "green")) +
geom_errorbar(data = df1[1:3,], aes(ymin=len-se, ymax=len+se), width=.4, colour=c("deepskyblue1"), position=position_dodge(.9)) +
geom_errorbar(data = df1[4:6,], aes(ymin=len-se, ymax=len+se), width=.4, colour=c("green"), position=position_dodge(.9))