如何得到

aaa<-data.frame(x=c("1","1","1","2","2","3"),y=c("A","B","A","C","C","A"))
希望得到数据框为：
x y freq
1 A  2
1 B  1
2 C  2
3 A  1
谢谢！

1. aaa<-data.frame(x=c("1","1","1","2","2","3"),y=c("A","B","A","C","C","A"))
   
2. b=as.data.frame(table(aaa))
   
3. bb=b[b$Freq!=0,]
   
4. bb

复制代码

再加一句
bb[order(bb$x),]