search for: conditional_time

...point me toward an R function/package that could speed up my processing time. Thanks a lot for your help! ## My dataframe includes the variables 'year', 'id', and 'eif' and has +/- 1.9 million id-year observations I would like to do 2 things: -1- I want to create a 'conditional_time' variable, which increases in increments of 1 every year, but which resets during year(t) if event 'eif' occured for this 'id' at year(t-1). It should also reset when we switch to a new 'id'. For example: dataframe = test year id eif conditional_time 1...