Yes,this is my final solution,but if I wanna add many new variables,and maybe the following "new variables" are computed based on the previous " new variables", this solution maybe difficult.
At 2012-12-24 17:01:03,arun <smartpink...@yahoo.com> wrote: >HI, > >Not sure if this works for you. >set.seed(5) >dat<-data.frame(x=sample(1:20,6,replace=TRUE),a=sample(20:40,6,replace=TRUE)) > dat1<-transform(dat,f=a/median(a),x_new=x*(a/median(a))) > head(dat1,2) ># x a f x_new >#1 5 31 1.016393 5.081967 >#2 14 36 1.180328 16.524590 >A.K. > > > > >----- Original Message ----- >From: meng <laomen...@163.com> >To: r-help@r-project.org >Cc: >Sent: Monday, December 24, 2012 12:55 AM >Subject: [R] How to do it through 1 step? > >A data set(dat),has 2 variables: x and a, and 100 rows. > >I wanna add 2 variables,and call the new data set dat1: >var1:f = a/median(a) >var2:x_new = x*f > >My solution: >dat1<-transform(dat,f = a/median(a),x_new = x*f) >But gets error reply which says that "f" is not exits since dat has no >variables called "f". > >So I have to do through 2 steps: >dat0<-transform(dat,f=a/median(a)) >dat1<-transform(dat0,x_new=x*f) > >How to do it through 1 step? > >Many thanks! > > > [[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. > [[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.
