Re: [R] reodering factor Hi John, You should use (http://rweb.stat.umn.edu/R/library/stats/html/relevel.html), so newGroup <- relevel (data$Group, ref = "ZZ") Reza On 5/3/07, John Sorkin  wrote: > R 2.4.1 > Windows XP > > How does one reorder a factor? > > > I have the following data: > > factor(data$Group) >  [1] ZZ ZT ZT ZZ ZZ ZT ZZ ZZ ZT ZT ZT ZT ZZ ZT ZT ZZ ZT ZZ ZT ZZ ZT ZT ZZ ZZ ZT ZZ ZT ZZ ZT ZZ ZZ ZT ZZ ZT > Levels: ZT ZZ > > In my regression (i.e. lm(y~data$Group) ZT is taken as the reference category and I get an estimate for ZZ. I would like ZZ to be the reference category and obtain an estimate for ZT. > > Thank, > John > > John Sorkin M.D., Ph.D. > Chief, Biostatistics and Informatics > University of Maryland School of Medicine Division of Gerontology > Baltimore VA Medical Center > 10 North Greene Street > GRECC (BT/18/GR) > Baltimore, MD 21201-1524 > (Phone) 410-605-7119 > (Fax) 410-605-7913 (Please call phone number above prior to faxing) > > Confidentiality Statement: > This email message, including any attachments, is for the so...{{dropped}} > > ______________________________________________ > 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 > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.