i have a data frame:
df = tibble(a=c(7,6,10,12,12), b=c(3,5,8,8,7), c=c(4,4,12,15,20), week=c(1,2,3,4,5))
# A tibble: 5 x 4
a b c week
<dbl> <dbl> <dbl> <dbl>
1 7 3 4 1
2 6 5 4 2
3 10 8 12 3
4 12 8 15 4
5 12 7 20 5
and i want for every column a, b and c the week in which the observation is equal to or exceeds 10.
I.e. for column a it would be week 3, for column b it would be week NA, for column c it would be week 3 as well.
A desired ouotcome could look like this:
tibble(abc=c("a", NA, "b"), value=c(10, NA, 12), week=c(3, NA, 3))
# A tibble: 3 x 3
abc value week
<chr> <dbl> <dbl>
1 a 10 3
2 b NA NA
3 c 12 3