dataframe - How to extract create daily first boarding record in R -

i have dataframe this, contains passenger id, date, , origin location.

id  date        origin  1   01/01/2012  1   01/01/2012  b 1   01/01/2012  c 1   01/02/2012  1   01/02/2012  b 1   01/02/2012  c 1   01/03/2012  1   01/03/2012  b 1   01/08/2012  2   01/01/2012  d 2   01/01/2012  c 2   01/01/2012  b 2   01/04/2012  d 2   01/04/2012  c 2   01/06/2012  d 3   01/03/2012  f 3   01/03/2012  g 3   01/09/2012  f 3   01/09/2012  g 

i want creat 'daily first boarding record' using datafram shown above

id date        origin     1   01/01/2012      1   01/02/2012      1   01/03/2012      1   01/08/2012      2   01/01/2012  d     2   01/04/2012  d     2   01/06/2012  d     3   01/03/2012  f     3   01/09/2012  f 

group id , date, taking first value origin in each group.

currently, i'm using code

daily_first_record = aggregate(origin ~ id + date, data=df, fun='[', i=1) 

however, code running because original dataset quite large (about 1gb csv). there easy way conduct same job?

we can use dplyr

library(dplyr) df1 %>%      group_by(id, date) %>%     summarise(origin = first(origin))