R满足条件时开始分组计数

Question

df <- data.frame (id  = c(1,1,1,2,2,2,3,3,3,3,4,4,4,4,4,4),
qresult=c(0,0,0,0,1,0,0,0,1,0,1,0,0,0,0,0),
count=c(0,0,0,0,1,2,0,0,1,2,1,2,3,4,5,6))
> df
id qresult count
1   1       0     0
2   1       0     0
3   1       0     0
4   2       0     0
5   2       1     1
6   2       0     2
7   3       0     0
8   3       0     0
9   3       1     1
10  3       0     2
11  4       1     1
12  4       0     2
13  4       0     3
14  4       0     4
15  4       0     5
16  4       0     6

如何获得count列，当q_result==1满足条件时开始计数，并为每个新的id重置?

Answer 1

我们可以在分组

之后在逻辑向量上使用双cumsum封装

library(dplyr)
df %>% 
group_by(id) %>%
mutate(count2 = cumsum(cumsum(qresult))) %>%
ungroup

与产出

# A tibble: 16 × 4
id qresult count count2
<dbl>   <dbl> <dbl>  <dbl>
1     1       0     0      0
2     1       0     0      0
3     1       0     0      0
4     2       0     0      0
5     2       1     1      1
6     2       0     2      2
7     3       0     0      0
8     3       0     0      0
9     3       1     1      1
10     3       0     2      2
11     4       1     1      1
12     4       0     2      2
13     4       0     3      3
14     4       0     4      4
15     4       0     5      5
16     4       0     6      6