Hi, I have something very interesting: Say I have this:
GroupID Date 1 1 10-Dec-12 2 1 11-Dec-12 3 2 13-Dec-12 4 2 15-Dec-12 5 3 06-Dec-12 6 3 19-Dec-12 Now, I have time interval, week 1: from 9-Dec-12 to 15-Dec-12, week 2: from 16-Dec-12 to 22-Dec-12, and so on. Obviously, the 1st, 2nd, 3rd, 4th row falls to week 1, 5th rows should not be counted, 6th row falls into week2. Therefore, by GroupID, I will have GroupID=1, Week1=2, Week2=0 GroupID=2, Week1=2, Week2=0 GroupID=3, Week1=0, Week2=1. I just want to count the valid date that falls into a 7-day week interval, and I shall have new variables for EACH WEEK, and the counts for dates that fall into this week interval. Can anyone please help me on programming this? W [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.