我有以下数据帧结构:
Animal Food
1 cat fish, milk, shrimp
2 dog steak, poo
3 fish seaweed, shrimp, krill, insects我想把它重新整理一下,使行按“食品”栏中因素数量的递减顺序排列:
Animal Food
1 fish seaweed, shrimp, krill, insects
2 cat fish, milk, shrimp
3 dog steak, poo有没有一个R函数能帮我解决这个问题?谢谢
发布于 2013-12-31 17:26:39
您可以根据计数功能的结果对帧进行排序:
animals = data.frame( rbind(c("cat","fish, milk, shrimp"),
c("dog","steak, poo"),
c("fish","seaweed, shrimp, krill, insects")))
colnames(animals) = c("Animal","Food")
animals[order(sapply(animals$Food, function(x) { length(strsplit(as.character(x),split=",")[[1]]) })), ]我输入as.character是因为它默认为一个因素,您可能不需要它(更快),或者在创建数据框架时可以使用stringsAsFactors=FALSE。
https://stackoverflow.com/questions/20860874
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