Add unique row identifiers to grouped long data

Question

I have the following dataframe which I am trying to prepare for pivoting.

Identifier	Data
X0001	A
X0002	B
X0002	C
X0003	G
X0004	B
X0005	B
X0005	C
X0005	D

I'm trying to add a count for the number of times the same identifier has appeared as a 3rd column which I can then use as column headers to pivot the data.

Identifier	Data	Count
X0001	A	1
X0002	B	1
X0002	C	2
X0003	G	1
X0004	B	1
X0005	B	1
X0005	C	2
X0005	D	3

Final Pivoted Version

Identifier	1	2	3
X0001	A
X0002	B	C
X0003	G
X0004	B
X0005	B	C	D

would greatly appreciate if someone has any ideas on how I can add the Count column required.

Thanks.

score 0 · Answer 1 · answered Apr 06 '21 at 05:46

df %>% group_by(Identifier) %>%
  mutate(d = row_number()) %>%
  pivot_wider(id_cols = Identifier, names_from = d, values_from = Data)

# A tibble: 5 x 4
# Groups:   Identifier [5]
  Identifier `1`   `2`   `3`  
  <chr>      <chr> <chr> <chr>
1 X0001      A     NA    NA   
2 X0002      B     C     NA   
3 X0003      G     NA    NA   
4 X0004      B     NA    NA   
5 X0005      B     C     D

Add unique row identifiers to grouped long data

1 Answers1