Say I have a df
df = data.frame(a = c('a', 'a','a','b','b','b'))
> df
a
1 a
2 a
3 a
4 b
5 b
6 b
I want to code the same group of data to the same serial number.
I tried this:
df %>% group_by(a) %>% mutate(id = row_number())
# A tibble: 6 x 2
# Groups: a [2]
a id
<chr> <int>
1 a 1
2 a 2
3 a 3
4 b 1
5 b 2
6 b 3
But this is not I wanted. What I wanted is like this ：
df_wanted = data.frame(a = c('a', 'a','a','b','b','b'),
id = c(1,1,1,2,2,2))
df_wanted
a id
1 a 1
2 a 1
3 a 1
4 b 2
5 b 2
6 b 2
Any help will be highly appreciated!
