r - R 中的订单条形图

Question

我正在尝试在 R 中绘制以下数据集:

fruit<-matrix(c("Apple","186","Banana","93","Elderberry","48","Durian", "28","Cherry", "28"),ncol=2,byrow=TRUE)
colnames(fruit) <- c("Name","Freq")
fruit <- data.table(fruit)
fruit$Freq  <- as.numeric(as.character(fruit$Freq))
qplot(fruit$Name, fruit$Freq, geom="bar", stat="identity") + coord_flip()

但它是按字母顺序绘制的

我希望条形图显示从最高频率值到最低频率值的水果。所以 Apple 位于 Y 轴顶部，然后是 Banana，等等...:

 Apple       186
 Banana      93
 Elderberry  48
 Durian      28
 Cherry      28

我尝试过使用因素和级别，但无法弄清楚。

Answer 1

使用reorder按Freq排序Name:

ggplot(fruit, aes(reorder(Name, Freq), Freq)) + 
   geom_bar(fill=hcl(195,100,65), stat="identity") + coord_flip() +
   xlab("Fruit") + ylab("Frequency")

如果您想要Name的任意顺序，您可以使用factor手动完成:

fruit$Name = factor(fruit$Name, 
                    levels=c("Banana", "Durian", "Elderberry", "Apple", "Cherry"))

# Now ggplot will plot the bars in the order listed in the factor command
ggplot(fruit, aes(Name, Freq)) + geom_bar(stat="identity") + coord_flip()

最后一件事:您可以使用更少的代码创建数据框。例如:

fruit = data.frame(Name=c("Apple","Banana", "Elderberry", "Durian", "Cherry"),
                   Freq=c(186, 93, 48, 28, 28))