Adding 6 hours in R dataframe using an UDF

Question

I have the below dataframe:

For Country = Hong Kong or Macau, I need to add 6 hours.

Input

number	indate	country
1	2020-05-05 7:41:28.277	Hong Kong
2	2020-05-05 17:41:28.277	China
3	2020-05-05 19:41:28.277	Macau
4	2020-05-05 17:41:28.277	China
5	2020-05-05 17:41:28.277	USA
6	2020-05-05 22:41:28.277	Hong Kong

Desired output:

number	indate	country	indate1
1	2020-05-05 7:41:28.277	Hong Kong	2020-05-05 13:41:28.277
2	2020-05-15 17:41:28.277	China	2020-05-15 17:41:28.277
3	2020-05-12 19:41:28.277	Macau	2020-05-13 01:41:28.277
4	2020-05-25 17:41:28.277	China	2020-05-25 17:41:28.277
5	2020-05-05 17:41:28.277	USA	2020-05-05 17:41:28.277
6	2020-05-13 22:41:28.277	Hong Kong	2020-05-14 04:41:28.277

Below is the code I have written:

library(lubridate)

hour_addition = function(dataf) {
        country = dataf[3]
        date= dataf[2]
        if (country == 'Hong Kong' | country = 'Macau'){
        date=as_datetime(date)
        date1 = date+dhours(6)
        date1 = as.character(date1)
        } else {
                date1 = date
        }
            return (date1)
        }
        
    new_date = apply(df,1,hour_addition)    
    df$indate1=new_date

I am not getting the desired results, Thanks in Advance. :)

Please provide your data in a reproducible format: https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example — Ben G, Aug 25 '21 at 14:31
Don't use apply. It will mangle your dataframe. instead just work with the indate column. `Input$Indate1 <- Input$indate+dhours(6)` — IRTFM, Aug 25 '21 at 20:21
@IRTFM the condition is if the country is equal to Hong Kong and Macau then only add 6 hour, rest all cases use the existing indate. — vik, Aug 26 '21 at 03:53

Arthur G. · Answer 1 · 2021-08-26T07:53:36.423

0

Do you need to do it with UDF? It is much easier with dplyr package:

library(dplyr)
library(lubridate)

df <- data.frame(
  number = c(1,2,3,4,5,6)
  ,indate = c('2020-05-05 17:41','2020-05-05 17:41','2020-05-05 17:41','2020-05-05 17:41','2020-05-05 17:41','2020-05-05 17:41')
  ,country = c("Hong Kong","China","Macau","China","USA","Hong Kong")
)

df <- df %>% 
  mutate(indate = ymd_hm(indate)
                ,indate1 = if_else(country %in% c('Hong Kong','Macau'), indate + hours(6), indate) )

edited Aug 26 '21 at 07:53

answered Aug 25 '21 at 15:05

Arthur G.

93
1
10

the condition is if the country is equal to Hong Kong and Macau then only add 6 hour, rest all cases use the existing indate. – vik Aug 26 '21 at 03:52
"If_else" is the function you are looking for. I've just updated my solution. – Arthur G. Aug 26 '21 at 07:55
G, I have asked a continuation question can u please look into it. – vik Aug 26 '21 at 14:33

Adding 6 hours in R dataframe using an UDF

1 Answers1