Dear list, would anybody be able to tell me why the statement Tripstatistics=aggregate(TripsData[2:3],by=list(Trip=Tripmatch),FUN="mean") seems to work well with TripsData 1 but not with TripsData 2 ? With TripsData 2 it yields Error in FUN(X[[1L]], ...) : arguments must have same length
I can't see a difference in the two data sets. Could someone shed light on the error message ? Maybe that would help me figure out where the problem is. Thanks very much for any help. Juliane PS: The examples below contain the first 5 rows of my two datafiles. TripsData 1 Trip Distance TimeDiff Tripmatch 7329 35,36 172.7453 0.0041 35,36 7371 36,35 172.7453 0.0004 35,36 7372 35,36 172.7453 0.0000 35,36 7373 36,35 172.7453 0.0004 35,36 7374 35,36 172.7453 0.0001 35,36 TripsData 2 Trip Distance TimeDiff Tripmatch 1617 19,20 1087.365 0.0441 19,20 1899 20,19 1087.365 0.0207 19,20 1915 19,20 1087.365 0.0361 19,20 3285 20,19 1087.365 0.0356 19,20 3826 19,20 1087.365 0.0697 19,20 ______________________________________________ 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.