How to fill in missing dates by minute by group in R

Question

I am attempting to fill in missing minutes from a dataframe that has different groups. I would like the missing minutes to be filled in with zeroes.

I tried to use this R - Fill missing dates by group but cannot find a way to fill in missing minutes.

Datetime            | Group | Value |
2019-01-01 00:00:00 |  1    |  5    |
2019-01-01 00:00:00 |  2    |  4    |
2019-01-01 00:00:00 |  3    |  2    | 
2019-01-01 00:01:00 |  1    |  1    |
2019-01-01 00:02:00 |  1    |  2    | 
2019-01-01 00:02:00 |  2    |  2    |
2019-01-01 00:02:00 |  3    |  1    |
2019-01-01 00:03:00 |  1    |  1    |
2019-01-01 00:03:00 |  2    |  2    |
2019-01-01 00:04:00 |  1    |  1    |

I would like the final table to look like this -

Datetime            | Group | Value |
2019-01-01 00:00:00 |  1    |  5    |
2019-01-01 00:00:00 |  2    |  4    |
2019-01-01 00:00:00 |  3    |  2    | 
2019-01-01 00:01:00 |  1    |  1    |
2019-01-01 00:01:00 |  2    |  0    | 
2019-01-01 00:01:00 |  3    |  0    |
2019-01-01 00:02:00 |  1    |  2    |
2019-01-01 00:02:00 |  2    |  2    |
2019-01-01 00:02:00 |  3    |  1    |
2019-01-01 00:03:00 |  1    |  1    |
2019-01-01 00:03:00 |  2    |  2    |
2019-01-01 00:03:00 |  3    |  0    |
2019-01-01 00:04:00 |  1    |  1    |
2019-01-01 00:04:00 |  2    |  0    |
2019-01-01 00:04:00 |  3    |  0    |

Answer 1

library(dplyr); library(padr)
df %>%
  pad(group = 'Group', interval = 'min') %>%   # Explicitly fill by 1 min
  fill_by_value(Value)

#pad applied on the interval: min
#              Datetime Group Value
#1  2019-01-01 00:00:00     1     5
#2  2019-01-01 00:01:00     1     1
#3  2019-01-01 00:02:00     1     2
#4  2019-01-01 00:03:00     1     1
#5  2019-01-01 00:04:00     1     1
#6  2019-01-01 00:00:00     2     4
#7  2019-01-01 00:01:00     2     0    # added
#8  2019-01-01 00:02:00     2     2
#9  2019-01-01 00:03:00     2     2
#10 2019-01-01 00:00:00     3     2
#11 2019-01-01 00:01:00     3     0    # added
#12 2019-01-01 00:02:00     3     1

---

Data

df <- read.table(
  header = T,
  stringsAsFactors = F, sep = "|",
  text = "Datetime            | Group | Value
2019-01-01 00:00:00 |  1    |  5  
2019-01-01 00:00:00 |  2    |  4    
2019-01-01 00:00:00 |  3    |  2     
2019-01-01 00:01:00 |  1    |  1  
2019-01-01 00:02:00 |  1    |  2     
2019-01-01 00:02:00 |  2    |  2    
2019-01-01 00:02:00 |  3    |  1    
2019-01-01 00:03:00 |  1    |  1    
2019-01-01 00:03:00 |  2    |  2    
2019-01-01 00:04:00 |  1    |  1"
) 
df$Datetime = lubridate::ymd_hms(df$Datetime)