我有一个数据框,每个ID都有多个条目。 ID具有引用号(NEW_REF)和旧引用号(OLD_REF)。我需要找到每个ID的最新参考编号,这意味着参考编号不在旧参考编号列中。
ID <- c(1,2,3,4,1,3,5,2,4,1,3,4)
NEW_REF <- c("TS101","TS253","TS565","TS789","TD123","TS101","TD367","TH152","TD123","TF908","TD256","TS898")
OLD_REF <- c("TD123","TH152","TS101","TD123","TF908","TD256","TG232","TR142","TS898","TR268","TB496","TD969")
DF <- data.frame(ID,NEW_REF ,OLD_REF )
DF$Active_ind <- NA
DF$Active_ind[which(DF$NEW_REF %in% DF$OLD_REF )] <-"N" #if a reference number is in the old reference number column it is not active or not the most recent
DF$Active_ind[which(!(DF$NEW_REF %in% DF$OLD_REF ))] <-"Y" #if a reference number is not in the old reference number column it is active or the most recent
ID NEW_REF OLD_REF Active_ind
1 1 TS101 TD123 N
2 2 TS253 TH152 Y
3 3 TS565 TS101 Y
4 4 TS789 TD123 Y
5 1 TD123 TF908 N
6 3 TS101 TD256 N
7 5 TD367 TG232 Y
8 2 TH152 TR142 N
9 4 TD123 TS898 N
10 1 TF908 TR268 N
11 3 TD256 TB496 N
12 4 TS898 TD969 N
我的问题是ID 1有一个新的参考TS101(第1行),而ID 3有一个旧的参考TS101(第3行)。如果参考号不是唯一的,如何查看哪个参考号是最近的每个ID 。
我希望第1行在Active_ind列中有一个Y:
ID NEW_REF OLD_REF Active_ind
1 1 TS101 TD123 Y
2 2 TS253 TH152 Y
3 3 TS565 TS101 Y
4 4 TS789 TD123 Y
5 1 TD123 TF908 N
6 3 TS101 TD256 N
7 5 TD367 TG232 Y
8 2 TH152 TR142 N
9 4 TD123 TS898 N
10 1 TF908 TR268 N
11 3 TD256 TB496 N
12 4 TS898 TD969 N
我知道有可能使用for循环,但我想避免它,因为我的数据集有超过40 000个不同的ID,并且在使用循环时变得非常耗时。
答案 0 :(得分:0)
我们可以使用dplyr
按ID
对其进行分组,然后检查NEW_REF
中OLD_REF
中的值是否存在,并相应地为其提供值。
library(dplyr)
DF %>%
group_by(ID) %>%
mutate(Active_Ind = ifelse(NEW_REF %in% OLD_REF, "N", "Y"))
# ID NEW_REF OLD_REF Active_Ind
# <dbl> <fctr> <fctr> <chr>
# 1 TS101 TD123 Y
# 2 TS253 TH152 Y
# 3 TS565 TS101 Y
# 4 TS789 TD123 Y
# 1 TD123 TF908 N
# 3 TS101 TD256 N
# 5 TD367 TG232 Y
# 2 TH152 TR142 N
# 4 TD123 TS898 N
# 1 TF908 TR268 N
# 3 TD256 TB496 N
# 4 TS898 TD969 N