dat1<- read.table(text=" Date Time Var 11/1/2012 1 3 11/1/2012 1 1 11/1/2012 1 1 11/1/2012 2 3 11/1/2012 2 1 11/1/2012 2 1 11/2/2012 1 1 11/2/2012 1 3 11/2/2012 1 1 11/2/2012 2 3 ",sep="",header=TRUE,stringsAsFactors=FALSE) dat1$Date<-as.Date(dat1$Date,format="%m/%d/%Y")
If you need to combine Date and Time columns into one: library(plyr) res<-mutate(ddply(dat1,.(Date,Time),summarize,Var=sum(Var)),DT=paste(Date,Time,sep="_"))[,c(4,3)] res # DT Var #1 2012-11-01_1 5 #2 2012-11-01_2 5 #3 2012-11-02_1 5 #4 2012-11-02_2 3 A.K. ________________________________ From: Ye Lin <ye...@lbl.gov> To: arun <smartpink...@yahoo.com> Cc: R help <r-help@r-project.org> Sent: Wednesday, May 29, 2013 2:40 PM Subject: Re: [R] combine two columns into one The actual "date" col is in yyyy-mm-dd format, and when I apply this code to my actual data, it mess up the order On Wed, May 29, 2013 at 11:37 AM, arun <smartpink...@yahoo.com> wrote: > >Hi, >May be I misunderstood your question: >dat<- read.table(text=" > >Date Time Var >1 1 2 >1 1 4 >1 1 5 >1 2 8 >1 2 8 >1 2 9 >2 1 3 >2 1 4 >2 1 4 >",sep="",header=TRUE) > >dat$UniqueID <- paste(dat$Date,dat$Time, sep = '_') > aggregate(dat$Var,list(dat$UniqueID),sum) #isn't this the correct order ># Group.1 x >#1 1_1 11 >#2 1_2 25 >#3 2_1 11 >library(plyr) >ddply(dat,.(UniqueID),summarize,Var=sum(Var)) ># UniqueID Var >#1 1_1 11 >#2 1_2 25 >#3 2_1 11 >A.K. > > > > >----- Original Message ----- >From: Ye Lin <ye...@lbl.gov> >To: R help <r-help@r-project.org> >Cc: >Sent: Wednesday, May 29, 2013 2:23 PM >Subject: [R] combine two columns into one > >Hey all! > >I have a time series dataset like this: > >Date Time Var >1 1 2 >1 1 4 >1 1 5 >1 2 8 >1 2 8 >1 2 9 >2 1 3 >2 1 4 >2 1 4 > >I created a unique id for each row: >dat$UniqueID <- paste(dat$Date,dat$Time, sep = '_') > >then > >aggregate(dat$Var, list(dat$UniqueID), sum) > >however the final output is not in ideal order I look for (I simply this >example provided above).I would like to have order like this: > >1_1 >1_2 >2_1 > >Thanks for your help! > > [[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. > > ______________________________________________ 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.