separate one row into multiple based on value in row

Question

I am take a data frame similar to this:

GISBLong	GISBLat	B Flyway	B Month	Count of Birds
-85.41667	42.41667	3	6	3
-97.25000	36.0833	2	7	2

And change it into this:

GISBLong	GISBLat	B Flyway	B Month	Bird ID
-85.41667	42.41667	3	6	1.1
-85.41667	42.41667	3	6	1.2
-85.41667	42.41667	3	6	1.3
-97.25000	36.0833	2	7	2.1
-97.25000	36.0833	2	7	2.2

So split the rows by the number in the "Count of Birds". Currently 1 row represents multiple birds and I would like to have 1 row for each bird. Any thoughts or suggestions on a function to use? Thanks so much.

Answer 1

You could use dplyr and tidyr. Let df be your data.frame.

library(dplyr)
library(tidyr)

df %>%
  mutate(id=row_number()) %>%
  uncount(Count_of_Birds) %>%
  group_by(id) %>%
  mutate(Bird_ID = paste0(id, ".", row_number())) %>%
  ungroup() %>%
  select(-id)

returns

# A tibble: 5 x 5
  GISBLong GISBLat B_Flyway B_Month Bird_ID
     <dbl>   <dbl>    <dbl>   <dbl> <chr>  
1    -85.4    42.4        3       6 1.1    
2    -85.4    42.4        3       6 1.2    
3    -85.4    42.4        3       6 1.3    
4    -97.2    36.1        2       7 2.1    
5    -97.2    36.1        2       7 2.2  

Data

df <- readr::read_table2("GISBLong  GISBLat     B_Flyway    B_Month     Count_of_Birds
                         -85.41667  42.41667    3   6   3
                         -97.25000  36.0833     2   7   2")