I haven’t figured out how to put the coalesce_by_column
function inside the dplyr
pipeline, but this works:
coalesce_by_column <- function(df) {
return(coalesce(df[1], df[2]))
}
df %>%
group_by(A) %>%
summarise_all(coalesce_by_column)
## A B C D E
## <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 1 2 3 2 5
## 2 2 4 5 3 4
Edit: include @Jon Harmon’s solution for more than 2 members of a group
# Supply lists by splicing them into dots:
coalesce_by_column <- function(df) {
return(dplyr::coalesce(!!! as.list(df)))
}
df %>%
group_by(A) %>%
summarise_all(coalesce_by_column)
#> # A tibble: 2 x 5
#> A B C D E
#> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 1 2 3 2 5
#> 2 2 4 5 3 4