R 如何在ggplot中将连续的x轴更改为离散的x轴

我有以下数据帧:

df = structure(list(qCountry = c("AT", "DE", "ES", "FI", "FR", "GR", 
"HU", "IR", "IT", "LV", "NL", "POL", "PT", "RO", "SWE"), Mean = c(1.34199395770393, 
1.37664132688321, 1.29144095341278, 1.42088404868674, 1.45019920318725, 
1.29786200194363, 1.24528301886792, 1.26937046004843, 1.38345864661654, 
1.39706780696396, 1.38751714677641, 1.30804248861912, 1.28609062170706, 
1.2320819112628, 1.32588699080158), Sd = c(0.474520963779525, 
0.484711259139164, 0.454549282145671, 0.493859200850428, 0.497678958439859, 
0.45742966912063, 0.430377930416405, 0.443767080631815, 0.48638085640142, 
0.489439780963027, 0.487350499450418, 0.461801022550429, 0.452051373271304, 
0.422281105345888, 0.468859354590332)), class = c("tbl_df", "tbl", 
"data.frame"), row.names = c(NA, -15L))

我想结合geom_point和geom_errorbar来绘制它.这不是问题.然而，x轴是一个连续变量，而我希望ggplot只显示1和2对应的两个标签"是"和"否".我try 了以下方法，但无效:

df %>% ggplot(aes(x = reorder(qCountry,-Mean), y = Mean, group = qCountry)) + geom_point(size = 3.5) +
  geom_errorbar(aes(ymin=Mean-Sd, ymax=Mean+Sd)) + labs(title = "Some Title",x = "", y="") + scale_y_discrete(labels= c("Yes", "No")) + coord_flip() + theme_classic2()

有人能帮我吗？

谢谢