数据框中的条件计数

Question

I have a dataframe (df) with the following structure

ID person_id person_type    proof_id
A1 P1        applicant      A1321
A1 P1        applicant      A423412
A1 P1        applicant      W352352
A1 P2        co_applicant   D43252
A1 P2        co_applicant   G43222
A2 P5        applicant      K5647
A2 P5        applicant      Pu7e5
A2 P6        co_applicant   L032u4
A2 P7        co_applicant   Q3344

I am trying to add another column to distinguish between the two person_co_applicant

ID person_id person_type    proof_id    final
A1 P1        applicant      A1321       applicant1
A1 P1        applicant      A423412     applicant1
A1 P1        applicant      W352352     applicant1
A1 P2        co_applicant   D43252      co_applicant1
A1 P2        co_applicant   G43222      co_applicant1
A2 P5        applicant      K5647       applicant1
A2 P5        applicant      Pu7e5       applicant1
A2 P6        co_applicant   L032u4      co_applicant1
A2 P7        co_applicant   Q3344       co_applicant2

I tired the following but this increments for every row:

df <- df %>% group_by(ID, person_type, person_id ) %>% 
  mutate(final = paste(person_type, 1:n()))

Answer 1

You are certainly looking for grouping only by ID and person_type :

library(data.table)

setDT(df)[, final:=paste0(person_type,1:length(unique(person_id))),.(ID, person_type)]

With dplyr you can use n_distinct :

df %>% 
    group_by(ID, person_type) %>% 
    mutate(final=paste0(person_type, 1:n_distinct(person_id)))

Answer 2

You could use data.table with ?rleid :

library(data.table)
setDT(df)[,final := paste0(person_type, rleid(person_id)), 
           by = c("ID", "person_type")]
> df
   ID person_id  person_type proof_id         final
1: A1        P1    applicant    A1321    applicant1
2: A1        P1    applicant  A423412    applicant1
3: A1        P1    applicant  W352352    applicant1
4: A1        P2 co_applicant   D43252 co_applicant1
5: A1        P2 co_applicant   G43222 co_applicant1
6: A2        P5    applicant    K5647    applicant1
7: A2        P5    applicant    Pu7e5    applicant1
8: A2        P6 co_applicant   L032u4 co_applicant1
9: A2        P7 co_applicant    Q3344 co_applicant2