I'm trying to create dummy variable for whether a child is first born, and one for if the child is second born. My data looks something like this
ID MID CMOB CYRB
1 1 1 1991
2 1 7 1989
3 2 1 1985
4 2 11 1985
5 2 9 1994
6 3 4 1992
7 4 2 1992
8 4 10 1983
With ID = child ID, MID = mother ID, CMOB = month of birth and CYRB = year of birth.
For the first born dummy I tried using this:
Identifiers_age <- Identifiers_age %>% group_by(MPUBID)
%>% mutate(first = as.numeric(rank(CYRB) == 1))
But there doesn't seem to be a way of breaking ties by the rank of another columnn (clearly in this case the desired column being CMOB), whenever I try using the "ties.method" argument it tell me the input must be a character vector.
Am I missing something here?
order might be more convenient to use here, from ?order:
order returns a permutation which rearranges its first argument into ascending or descending order, breaking ties by further arguments.
Identifiers_age <- Identifiers_age %>% group_by(MID) %>%
mutate(first = as.numeric(order(CYRB, CMOB) == 1))
Identifiers_age
#Source: local data frame [8 x 5]
#Groups: MID [4]
# ID MID CMOB CYRB first
# <int> <int> <int> <int> <dbl>
#1 1 1 1 1991 0
#2 2 1 7 1989 1
#3 3 2 1 1985 1
#4 4 2 11 1985 0
#5 5 2 9 1994 0
#6 6 3 4 1992 1
#7 7 4 2 1992 0
#8 8 4 10 1983 1