Dear Jorge, thank you very much for your help. So with() was missing.
Tripstatistics=with(TripsData,aggregate(TripsData[,3:4],by=list(Trip=Tripmatch),FUN="mean")) works. Best wishes, Juliane Dr. Juliane Struve Environmental Scientist 10, Lynwood Crescent Sunningdale SL5 0BL 01344 620811 ________________________________ From: Jorge Ivan Velez <jorgeivanve...@gmail.com> Cc: R mailing list <r-help@r-project.org> Sent: Thursday, 24 September, 2009 13:32:59 Subject: Re: [R] aggregate() - error message Hi Julien, Works for me: # Data sets TripsData1 <- read.table(textConnection("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"), header = TRUE) TripsData2 <- read.table(textConnection("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"), header = TRUE) closeAllConnections() # Individually with(TripsData1, aggregate(TripsData1[, 2:3], by = list(Tripmatch), FUN="mean") ) # Group.1 Distance TimeDiff # 1 35,36 172.7453 0.001 with(TripsData2, aggregate(TripsData2[, 2:3], by = list(Tripmatch), FUN="mean") ) # Group.1 Distance TimeDiff # 1 19,20 1087.365 0.04124 # Combining both data sets AllTrips <- rbind(TripsData1, TripsData2) with(AllTrips, aggregate(AllTrips[, 2:3], by = list(Tripmatch), FUN="mean") ) # Group.1 Distance TimeDiff # 1 35,36 172.7453 0.00100 # 2 19,20 1087.3650 0.04124 HTH, Jorge On Thu, Sep 24, 2009 at 8:23 AM, Juliane Struve <> wrote: Dear all, > > >thanks you very much for replying. However, this does not seem to solve the >problem. >I still get the same error message when using TripsData[,2:3]. > >Is there anything else that could be wrong with this statement or the data ? >What length is the error message referring to ? > >Many thanks, > >Juliane > > > Dr. Juliane Struve >Environmental Scientist >10, Lynwood Crescent >Sunningdale SL5 0BL >01344 620811 > > > > >----- Original Message ---- >From: Paul Emberson <em...@calidasoft.co.uk> >Cc: r-help@r-project.org >Sent: Thursday, 24 September, 2009 12:27:00 >Subject: Re: [R] aggregate() - error message > >Hi, > >Are you trying to get columns 2 and 3 from TripsData in which case you need to >say TripsData[,2:3] ? > >Paul > >Juliane Struve wrote: >> 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. > > > > > [[alternative HTML version deleted]]
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