r - ggplot2 - 在堆积条形图中翻转级别的顺序

Question

这段代码相当少，应该能够调整为解决方案。

blah <- data.frame(X1=c("Decrease Risk","Don't Know","Increase Risk","No Effect","Decrease Risk","Don't Know","Increase Risk","No Effect"),
                   X2=c("Red Meat","Red Meat","Red Meat","Red Meat","Red Meat","Red Meat","Red Meat","Red Meat"),
                   value=c(1.98,31.19,64.38,2.43,4.65,24.55,35.88,34.90),
                   status=c("Case","Case","Case","Case","Control","Control","Control","Control")
                   )

ggplot(blah, aes(X2, value, fill=X1)) + geom_bar() + coord_flip() + facet_wrap(~status) + 
    labs(x="Perceived Risk Factors", y="Percentage (%)", tilte="Some Title", fill="Responses")

我想要的是右侧的“控件”将“响应”级别的顺序颠倒过来。关键是，对于控件，紫色在里面，然后是蓝色的，然后是绿色的，外面是粉红色的。在这样的情节中这样做是半常见的，我可以想办法做到这一点，包括一些相当肮脏的变量重复和有序因子水平的改变，但认为有人可能有一个优雅的解决方案/想法？

Answer 1

这是一种使用顺序美学的略微微妙的方法。

ggplot(blah, aes(X2, value, fill = X1, 
  order = (3-as.numeric(status)*2) * as.numeric(X1))) + 
geom_bar() + coord_flip() + facet_wrap(~status) + 
labs(x="Perceived Risk Factors", y="Percentage (%)", title="Some Title", 
  fill="Responses")

这并不理想，因为当有两个以上的方面时，它不会那么容易地概括所有方面。