Hello everyone, My progress has stalled on finding a way of creating a somewhat complicated variable to add to my existing dataframe and I am hoping one of you could help me out. The dataframe below contains only a fraction of the data of my complete dataframe, but all of the variables. What I want to do is add another variable named 'WEEK' to this dataframe that is assigned 1 for row 1 and remains 1 until the first SAT (i.e. Saturday) under variable 'DOW' (day of week) occurs, at which point variable 'WEEK' is now assigned 2. 'WEEK' should continue to be assigned 2 until the following SAT under variable 'DOW' at which variable 'WEEK' will now be assigned 3, and so on. In this scheme, weekdays are such that SAT=1, SUN=2, MON=3,.....FRI=7. I am basically trying to assign week numbers to potential sampling days in a survey season for use in a program that will generate a fisheries creel survey schedule. I should note that if element 1 happens to have DOW=SAT (that is the case this year, since! the first day of our survey 05/01 is a Saturday), then WEEK 1 begins on day 1 (05/01/2010) and WEEK 2 will begin on the first SAT under variable DOW. I hope I explained this clearly enough, if not let me know.
Mike MM DD YR DOW DOW. DTYPE TOD TOD. SITENUM DESC 1 05 01 2010 SAT 1 2 MORN 1 101 WALNUT.CK 185 05 01 2010 SAT 1 2 MORN 1 102 LAMPE 369 05 01 2010 SAT 1 2 MORN 1 103 EAST.AVE 553 05 01 2010 SAT 1 2 MORN 1 104 NORTH.EAST 737 05 01 2010 SAT 1 2 AFTN 2 101 WALNUT.CK 921 05 01 2010 SAT 1 2 AFTN 2 102 LAMPE 1105 05 01 2010 SAT 1 2 AFTN 2 103 EAST.AVE 1289 05 01 2010 SAT 1 2 AFTN 2 104 NORTH.EAST 2 05 02 2010 SUN 2 2 MORN 1 101 WALNUT.CK 186 05 02 2010 SUN 2 2 MORN 1 102 LAMPE 370 05 02 2010 SUN 2 2 MORN 1 103 EAST.AVE 554 05 02 2010 SUN 2 2 MORN 1 104 NORTH.EAST 738 05 02 2010 SUN 2 2 AFTN 2 101 WALNUT.CK 922 05 02 2010 SUN 2 2 AFTN 2 102 LAMPE 1106 05 02 2010 SUN 2 2 AFTN 2 103 EAST.AVE 1290 05 02 2010 SUN 2 2 AFTN 2 104 NORTH.EAST 3 05 03 2010 MON 3 1 MORN 1 101 WALNUT.CK 187 05 03 2010 MON 3 1 MORN 1 102 LAMPE 371 05 03 2010 MON 3 1 MORN 1 103 EAST.AVE 555 05 03 2010 MON 3 1 MORN 1 104 NORTH.EAST 739 05 03 2010 MON 3 1 AFTN 2 101 WALNUT.CK 923 05 03 2010 MON 3 1 AFTN 2 102 LAMPE 1107 05 03 2010 MON 3 1 AFTN 2 103 EAST.AVE 1291 05 03 2010 MON 3 1 AFTN 2 104 NORTH.EAST 4 05 04 2010 TUE 4 1 MORN 1 101 WALNUT.CK 188 05 04 2010 TUE 4 1 MORN 1 102 LAMPE 372 05 04 2010 TUE 4 1 MORN 1 103 EAST.AVE . . . . . . . . . . . [[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.