R 合并两个创建的直方图以进行比较

我想比较各州两位不同候选人的选举结果（得票率），并用一张图表将其绘制出来

为此，我编写了以下文件：

swing.obama = filter(swing.states, Candidate == "Barack Obama")

swing.romney = filter(swing.states, Candidate != "Barack Obama")

par(mfrow=c(2,1))

ro.swing = barplot(swing.romney$Percentatge.of.Votes, names.arg = swing.romney$State.or.district,
                    col = "red2", main = "Results by State - Mitt Romney")

ob.swing = barplot(swing.obama$Percentatge.of.Votes, names.arg = swing.obama$State.or.district,
                   col = "darkblue", main = "Results by State - Barack Obama")

在这里，您可以在直方图中并排看到这两个结果

按国家分列的结果：

---

如何“合并”这两个文件以同时获得蓝色和红色条？

请测试此

ggplot2

解决方案：

library(ggplot2)
ggplot(swing.states, 
       aes(State.or.district, Percentatge.of.Votes, fill = Candidate)) +
geom_bar(stat = "identity", position = "dodge") +
labs(title = "Results by state",
     x = "State/district",
     y = "Votes, %")

---

请考虑格式化你的问题。