Adding missing date values in a data frame with multiple observation periods

Question

Thanks in advance.

I am trying to add missing date values that were not included in a observation period for three different individuals.

My data look like t

Answer 1

Calculate min and max times (seconds since Epoch):

min_time = as.integer(min(PostData$Date))
max_time = as.integer(max(PostData$Date))

Use sequence to build the list of missing dates:

list_of_dates = seq(min_time,max_time, 86400) #since there are 86400 seconds in a day
list_of_dates = as.Date(as.POSIXct( list_of_dates ), origin = '1970-01-01 00:00.00 UTC') 
#convert back to a date

Build a list of missing IndID and Date combos

temp = merge(unique(PostData$IndID),list_of_dates)
names(temp) = c("IndID","Date")
data_missing_indID_date = temp[!which(temp$IndID %in% PostData$IndID & temp$Date %in% PostData$Date ),]

Build the rest of the columns:

data_missing_indID_date$Event = 0 
data_missing_indID_date$Number = NA
data_missing_indID_date$Percent = NA

rbind it to the original data frame:

final_data = rbind(PostData, data_missing_indID_date)