使用下面的简单数据,我打算创建一个新列,其中包含一个1表示城市=“多伦多”和PostInjury = "0-1“的实例,2用于City=”蒙特利尔“和PostInjury ="6-10”的实例,还有一个3代表其他所有的实例。
我想使用mutate和if_else,但不确定如何使用这个组合有条件地将多个列组合重新编码成一个新列,而不需要中间步骤?我可以使用两个if_else语句来创建两个新列,然后将它们与Tidyr的unite组合起来,但这似乎非常乏味。
我错过了什么优雅的东西吗?我有种感觉是否有一种在dplyr中以这种方式使用if_else的方法,或者使用case_when的方法?
City<-c("Toronto", "Toronto", "Montreal","Ottawa","Montreal",
"Hamilton","Peterborough","Toronto","Hamilton","Montreal")
Client<-c("Cl1","Cl2","Cl3","Cl4","Cl5","Cl6","Cl7","Cl8","Cl9","Cl10")
PostInjury<-c("0-1","6-10","0-1","2-5","6-10","0-1","11-15","0-1","0-1","6-10")
DF<- data.frame(City,Client,PostInjury)
发布于 2016-10-26 05:31:15
您可以使用嵌套的ifelse
。用dplyr
DF <- DF %>%
mutate(new_column = if_else(City == "Toronto" & PostInjury == "0-1", 1,
if_else(City == "Montreal" & PostInjury == "6-10", 2, 3)))
使用case_when
DF <- DF %>% mutate(new_column =
case_when(
City == "Toronto" & PostInjury == "0-1" ~ 1,
City == "Montreal" & PostInjury == "6-10" ~ 2,
TRUE ~ 3
)
)
或者使用base
函数:
DF$new_column <- ifelse(DF$City == "Toronto" & DF$PostInjury == "0-1", 1,
ifelse(DF$City == "Montreal" & DF$PostInjury == "6-10", 2, 3))
或
DF$new_column <- sapply(as.character(interaction(DF$City, DF$PostInjury)),
switch,
"Toronto.0-1" = 1,
"Montreal.6-10" = 2,
3)
https://stackoverflow.com/questions/40254229
复制相似问题