Home Is there a good way to make the rest of value 1 within a id if the previous value is 1 in r

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Is there a good way to make the rest of value 1 within a id if the previous value is 1 in r

July 15, 2022

I am trying to make the rest of visit value to 1 if the previous value is 1 within the same id, but just can’t find a good way without a bunch of slow for loops.

Here is the example:

data.frame(ID = c(1,1,1,1,1,2,2,2,2,2,2,3,3,3), 
           Visit = c(1,2,3,4,5,1,2,3,4,5,6,1,2,3), 
           Value = c(0,0,1,0,0,0,0,0,0,1,0,0,1,0))

And here is what I want to get:

data.frame(ID = c(1,1,1,1,1,2,2,2,2,2,2,3,3,3), 
           Visit = c(1,2,3,4,5,1,2,3,4,5,6,1,2,3), 
           Value = c(0,0,1,1,1,0,0,0,0,1,1,0,1,1))

Thanks in advance!

>Solution :

We could use cummax to return 1 for rest of the values after grouping by ‘ID’

library(dplyr)
df1 %>% 
   group_by(ID) %>%
   mutate(Value = cummax(Value))%>%
   ungroup

-output

# A tibble: 13 × 3
      ID Visit Value
   <dbl> <dbl> <int>
 1     1     1     0
 2     1     2     0
 3     1     3     1
 4     1     4     1
 5     2     1     0
 6     2     2     0
 7     2     3     0
 8     2     4     0
 9     2     5     1
10     2     6     1
11     3     1     0
12     3     2     1
13     3     3     1