See inline below. -------------------------------------- Jonathan P. Daily Technician - USGS Leetown Science Center 11649 Leetown Road Kearneysville WV, 25430 (304) 724-4480 "Is the room still a room when its empty? Does the room, the thing itself have purpose? Or do we, what's the word... imbue it." - Jubal Early, Firefly
r-help-boun...@r-project.org wrote on 02/24/2011 01:23:54 PM: > [image removed] > > [R] create dummy variables by for loop > > Changbin Du > > to: > > <r-help@r-project.org> > > 02/24/2011 01:25 PM > > Sent by: > > r-help-boun...@r-project.org > > HI, Dear R community, > > I try to create 100 dummy variables like the following: > > ack$id_1 <- (ack$ID==1)*1 > ack$id_2 <- (ack$ID==2)*1 > .. > . > ack$id_100 <- (ack$ID==100)*1 > > > I used the following codes: > > for(i in 1:100){ > ack$id_[i] <- (ack$ID==i)*1 > } This doesn't do what you think it does. when i = 1, it assigns the result of (ack$ID==1)*1 to the first element of ack$id_ If you want ack$id_i to be created, try: ack[[paste("id", i, sep = "_")]] <- (ack$ID==i)*1 > > But only one column is created, can anyone help me? > > Thanks a lot! > > > -- > Sincerely, > Changbin > -- > > [[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.