Suppose we want to sum C over levels of A and that B is constant within levels of A. Then:
DF <- data.frame(A = gl(2,2), B = gl(2,2), C = 1:4) # test data do.call("rbind", by(DF, DF$A, function(x) replace(x[1,], "C", sum(x$C)))) On 5/3/06, Guenther, Cameron <[EMAIL PROTECTED]> wrote: > Hello, > > I have a data set with a grouping variable (TRIPID) and several other > variables. TRIPID is repeated in some areas and I would like to use a > function like aggregate to sum the variable UNITS according to TRIPID. > However I would also like to retain the other variables as they are in > the data set with the new summed TRIPID. > > So what I have is something like this: > > YEAR MONTH DAY CONTINUE SPL AREA COUNTY DEPTH > DEPUNIT GEAR GEAR2 TRAPS SOAKTIME UNITS FACTOR DISPOSIT > NUMSETS TRIPST TRIPID > 1992 1 26 1 SP0073928 8 > 25 4 NA 1000000 NA NA > NA 161 1 NA NA > NA 0216 3399054 1992 1 26 > 1 SP0073928 8 25 4 NA > 1000000 NA NA NA 8 > 1 NA NA NA 0216 3399054 > 1992 1 26 2 SP0004228 8 > 25 4 NA 1000000 NA NA > NA 161 1 NA NA > NA 0216 3399054 1992 1 26 > 2 SP0004228 8 25 4 NA > 1000000 NA NA NA 8 > 1 NA NA NA 0216 3399054 > 1992 1 25 NA SP0052652 8 > 25 4 NA 1000000 NA NA > NA 85 1 NA NA > NA 0216 3399057 1992 1 26 > NA SP0037940 8 25 4 NA > 1000000 NA NA NA 70 > 1 NA NA NA 0216 3399058 > 1992 1 27 NA SP0072357 8 > 25 4 NA 1000000 NA NA > NA 15 1 NA NA > NA 0216 3399059 > 1992 1 27 NA SP0072357 8 > 25 4 NA 1000000 NA NA > NA 20 1 NA NA > NA 0216 3399059 1992 1 27 > NA SP0026324 8 25 4 NA > 1000000 NA NA NA 8 > 1 NA NA NA 0216 3399060 > 1992 1 28 1 SP0072357 8 > 25 4 NA 1000000 NA NA > NA 200 1 NA NA > NA 0216 3399062 > > And what I want is this: > > YEAR MONTH DAY CONTINUE SPL AREA COUNTY DEPTH > DEPUNIT GEAR GEAR2 TRAPS SOAKTIME UNITS FACTOR DISPOSIT > NUMSETS TRIPST TRIPID > 1992 1 26 1 SP0073928 8 > 25 4 NA 1000000 NA NA > NA 338 1 NA NA > NA 0216 3399054 1992 1 25 > NA SP0052652 8 25 4 NA > 1000000 NA NA NA 85 > 1 NA NA NA 0216 3399057 > 1992 1 26 NA SP0037940 8 > 25 4 NA 1000000 NA NA > NA 70 1 NA NA > NA 0216 3399058 > 1992 1 27 NA SP0072357 8 > 25 4 NA 1000000 NA NA > NA 35 1 NA NA > NA 0216 3399059 > 1992 1 27 NA SP0026324 8 > 25 4 NA 1000000 NA NA > NA 8 1 NA NA > NA 0216 3399060 > 1992 1 28 1 SP0072357 8 > 25 4 NA 1000000 NA NA > NA 200 1 NA NA > NA 0216 3399062 > > > Does anyone know how to do this. Data file is attached. > Thanks in advance > > Cameron Guenther, Ph.D. > Associate Research Scientist > FWC/FWRI, Marine Fisheries Research > 100 8th Avenue S.E. > St. Petersburg, FL 33701 > (727)896-8626 Ext. 4305 > [EMAIL PROTECTED] > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html