Tena koe Sean I suspect the apply() and merge() functions are working, but they may not be doing what you expect :-) You could try rbind() and aggregate():
> data.frame1$HAD <- as.numeric(NA) > data.both <- rbind(data.frame1, data.frame2) > aggregate(data.both[,-(1:3)], data.both[,1:3], sum, na.rm=T) Season Gear Area COD POLL HAD 1 winter dredge 515 113 174 18 This assumes COD, POLL and HAD are numeric. HTH .... Peter Alspach > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Sean M. Lucey > Sent: Thursday, 21 January 2010 9:20 a.m. > To: r-help@r-project.org > Subject: [R] Merge and join data > > Hi, > > I'm looking to combine two data frames. Several of the > columns are in common while the others need to be summed up. > The apply functions and the merge functions don't seem to be > working. I've included a basic example of what I'm trying to > do below. Thanks! > > Sean > > > data.frame1<-as.data.frame(matrix(c('winter','dredge','515',10 > 0,150),1,5)) > names(data.frame1)<-c('Season','Gear','Area','COD','POLL') > > data.frame2<-as.data.frame(matrix(c('winter','dredge','515',13 > ,24,18),1,6)) > names(data.frame2)<-c('Season','Gear','Area','COD','POLL','HAD') > > > I'd like to end up with something that looks like this: > > Season Gear Area COD POLL HAD > winter dredge 515 113 174 18 > > Thanks, > Sean > > ______________________________________________ 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.