R find at least 10 consecutive 1s in a row

May 27, 2023

I have a column DuchenneMarker with the values 0 and 1.
I want to find at least 10 consecutive 1s and mark them in a new column DuchenneSmiles like this:

DuchenneMarker DuchenneSmiles
0              0
0              0            
0              0
1              0
1              0
0              0
1              1 
1              1 
1              1 
1              1 
1              1 
1              1 
1              1 
1              1 
1              1 
1              1 
1              1

I’ve already tried it with stats:filter() and dplyr::filter() but it didn’t worked.
Is there a function that I should use or a brute-force method?

>Solution :

With the tidyverse you could do something like this. It creates a dummy grouping variable run for each run of 0s or 1s and removes it at the end.

df %>% 
  group_by(run = cumsum(DuchenneMarker != lag(DuchenneMarker, default = 0))) %>% 
  mutate(DuchenneSmiles = 0L + (n() > 9 & DuchenneMarker == 1)) %>% 
  ungroup() %>% 
  select(-run)

# A tibble: 17 × 2
   DuchenneMarker DuchenneSmiles
            <int>          <int>
 1              0              0
 2              0              0
 3              0              0
 4              1              0
 5              1              0
 6              0              0
 7              1              1
 8              1              1
 9              1              1
10              1              1
11              1              1
12              1              1
13              1              1
14              1              1
15              1              1
16              1              1
17              1              1