找不到这个问题的解决方案,正在寻找一些指导。
这是我的一个数据集示例:
ID Rank Date Date2. Group Group2
1 5678 1 2000-01-01 2010-05-02 A A
2 5678 2 2010-05-02 2010-05-02 A A
3 1234 1 2000-01-01 2015-06-03 B A&B
4 1234 2 2015-06-03 2015-06-03 A A&B
我想按ID进行分组,并确定"组"列中是否存在该ID的多个值。如果是,请将它们连接在一起。
Group2是基于分组ID并查看Group中是否存在多个值的所需输出。我正在使用dplyr,但不确定从这里到哪里:
df <- df %>% group_by(ID) %>% mutate(Group2 = if else(?))
我认为最简单的方法是unique
函数。此函数创建一个向量,该向量具有给定的不同值。
> df %>%
group_by(ID)%>%
mutate(Group2=paste(sort(unique(Group)),
collapse="&"))
# A tibble: 4 x 3
# Groups: ID [2]
ID Group Group2
<dbl> <chr> <chr>
1 5678 A A
2 5678 A A
3 1234 B A&B
4 1234 A A&B
带有data.table
的选项
library(data.table)
setDT(df)[, Group2 := paste(sort(unique(Group)), collapse="&"), ID]
数据
df <- structure(list(ID = c(5678L, 5678L, 1234L, 1234L), Rank = c(1L,
2L, 1L, 2L), Date = c("2000-01-01", "2010-05-02", "2000-01-01",
"2015-06-03"), Date2. = c("2010-05-02", "2010-05-02", "2015-06-03",
"2015-06-03"), Group = c("A", "A", "B", "A")), row.names = c("1",
"2", "3", "4"), class = "data.frame")
我建议下一种方法:
library(dplyr)
#Code
df %>% group_by(ID) %>%
arrange(ID,Group) %>%
#Identify unique elements
mutate(NUnique=n_distinct(Group)) %>%
mutate(Group2=ifelse(NUnique>1,paste0(Group,collapse = '&'),Group))
输出:
# A tibble: 4 x 7
# Groups: ID [2]
ID Rank Date Date2. Group NUnique Group2
<int> <int> <chr> <chr> <chr> <int> <chr>
1 1234 2 2015-06-03 2015-06-03 A 2 A&B
2 1234 1 2000-01-01 2015-06-03 B 2 A&B
3 5678 1 2000-01-01 2010-05-02 A 1 A
4 5678 2 2010-05-02 2010-05-02 A 1 A
使用的一些数据:
#Data
df <- structure(list(ID = c(5678L, 5678L, 1234L, 1234L), Rank = c(1L,
2L, 1L, 2L), Date = c("2000-01-01", "2010-05-02", "2000-01-01",
"2015-06-03"), Date2. = c("2010-05-02", "2010-05-02", "2015-06-03",
"2015-06-03"), Group = c("A", "A", "B", "A")), row.names = c("1",
"2", "3", "4"), class = "data.frame")
基本R选项
within(df,Group2 <- ave(Group,ID,FUN = function(x) ifelse(length(unique(x))==1,x,paste0(x,collapse = "&"))))
给出
ID Rank Date Date2. Group Group2
1 5678 1 2000-01-01 2010-05-02 A A
2 5678 2 2010-05-02 2010-05-02 A A
3 1234 1 2000-01-01 2015-06-03 B B&A
4 1234 2 2015-06-03 2015-06-03 A B&A
继续使用您的代码,我会尝试:
df %>%
group_by(ID) %>%
mutate(Group2 = ifelse(n_distinct(Group) == 1, as.character(Group), paste0(sort(Group), collapse = "&")))
# A tibble: 4 x 6
# Groups: ID [2]
ID Rank Date Date2. Group Group2
<int> <int> <fct> <fct> <fct> <chr>
1 5678 1 2000-01-01 2010-05-02 A A
2 5678 2 2010-05-02 2010-05-02 A A
3 1234 1 2000-01-01 2015-06-03 B A&B
4 1234 2 2015-06-03 2015-06-03 A A&B