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的水果。所以Apple位于Y轴的顶部，然后是Banana等......：

 Apple       186
 Banana      93
 Elderberry  48
 Durian      28
 Cherry      28

我试图玩各种因素和水平，但无法弄清楚。

Answer 1

使用reorder按Name订购Freq：

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的任意排序，可以使用factor手动执行：

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))

Answer 2

除了@Richard Scriven之外，您还可以使用以下base代码进一步操纵条形图：

fruit <- fruit[order(Freq),]

par(mar = c(4,5,2,2))
barplot(fruit$Freq, xlim = c(0,200), xaxt = "n", space = 1, horiz = TRUE, 
        names.arg = fruit$Name, las = 2)

axis(1, at = seq(0,200,20))
mtext("Frequency (#)", 1, line = 2.5)