Ignore the previous post. I completely spaced out on which mailing list I was reading and thought this was a SAS question. My apologies, I'll just crawl back into my hole. :-)
Obviously not helpful, Dan Daniel J. Nordlund Research and Data Analysis Washington State Department of Social and Health Services Olympia, WA 98504-5204 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Nordlund, > Dan (DSHS/RDA) > Sent: Thursday, April 03, 2008 2:45 PM > To: [EMAIL PROTECTED]; r-help@r-project.org > Subject: Re: [R] coding for categorical variables with > unequal observations > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Tanya Yatsunenko > > Sent: Thursday, April 03, 2008 1:55 PM > > To: r-help@r-project.org > > Subject: [R] coding for categorical variables with unequal > > observations > > > > Hi, > > I am doing multiple regression, and have several X > variables that are > > categorical. > > I read that I can use dummy or contrast codes for that, but > are there > > any special rules when there're unequal #observations in each > > groups (4 > > females vs 7 males in a "gender" variable)? > > Also, can R generate these codes for me? > > THanks. > > > > You don't need to do anything special, and yes you can just > let SAS do it for you. For most of the regression PROCs you > can put your categorical variables in a CLASS statement. > Depending on which procedure you are using, you may be able > to specify whether you want effects or dummy coding, and > which level of the categorical variable should be the > "comparison" level. It is also possible to use PROC GLMMOD > to create your design variables to be fed into other PROCs. > Other approaches are possible as well. > > If you provide more detail on what analyses you plan to > undertake, someone may be able to provide more specific advice. > > Hope this is helpful, > > Dan > > Daniel J. Nordlund > Research and Data Analysis > Washington State Department of Social and Health Services > Olympia, WA 98504-5204 > > > > ______________________________________________ > 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.
