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rdata-management

Changing number of observation in a dataset by IDs according to a given value

I have this dataset in R:

enter image description here

and I want to change the data according to nb variable, it means ID = 1 will have 5 rows and ID=2 will have 12 rows as shown below:

enter image description here

is there any R function that I could use it to transform my data :) ?

Thanks in advance

Solution

  • We need uncount from tidyr to expand based on the 'nb' column, by default, it removes the column as .remove = TRUE, change it to FALSE and then create the nb_long by doing a group by row_number()

    library(dplyr)
library(tidyr)
df1 %>%
   uncount(nb, .remove = FALSE) %>%
   group_by(ID) %>%
   mutate(nb_long = row_number()) %>%
   ungroup

    -output

    # A tibble: 17 x 3
      ID    nb nb_long
   <int> <dbl>   <int>
 1     1     5       1
 2     1     5       2
 3     1     5       3
 4     1     5       4
 5     1     5       5
 6     2    12       1
 7     2    12       2
 8     2    12       3
 9     2    12       4
10     2    12       5
11     2    12       6
12     2    12       7
13     2    12       8
14     2    12       9
15     2    12      10
16     2    12      11
17     2    12      12

    data

    df1 <- structure(list(ID = 1:2, nb = c(5, 12)), 
class = "data.frame", row.names = c(NA, 
-2L))