我该怎么走
df<-data.frame(id=c("A", "B", "B"), res=c("one", "two", "three"))
df
到
df.output<-data.frame(id=c("A", "B"), res1=c("one", "two"), res2=c(NA, "three"))
df.output
dplyr美元？
I do not know a priori the number of duplicates in id (in this example B has 2 occurrences), so the number of resX variables in the output data frame has 到 be generated on the fly.
您只需要创建一个行标识符，可以使用dplyr，然后使用tidyr::pivot_wider()生成所有resX个变量.
library(dplyr)
library(tidyr)
df %>%
group_by(id) %>%
mutate(
no = row_number()
) %>%
ungroup() %>%
pivot_wider(
id,
names_from = no,
names_prefix = "res",
values_from = res
)
#> # A tibble: 2 × 3
#> id res1 res2
#> <chr> <chr> <chr>
#> 1 A one <NA>
#> 2 B two three