library(vcd)
library(grid)
counts<-table(Arthritis$Improved,Arthritis$Treatment)
counts
barplot(counts,
         main="Stacked Bar Plot",
         xlab="Treatment",ylab="Frequency",
         col=c("red","yellow","green"),
         legend=rownames(counts))#legend 提供标签

library(vcd)
library(grid)
counts<-table(Arthritis$Improved,Arthritis$Treatment)
counts
barplot(counts,
         main="Stacked Bar Plot",
         xlab="Treatment",ylab="Frequency",
         col=c("red","yellow","green"),
         legend=rownames(counts),beside = TRUE)#beside 表示矩阵中的每一列都表示一个分组，各列中的值将并列而不是堆砌

library(vcd)
library(grid)
attach(Arthritis)
counts<-table(Treatment,Improved)
counts
spine(counts,
         main="Stacked Bar Plot")
detach(Arthritis)