From: Doran, Harold <HDoran_at_air.org>

Date: Wed 07 Dec 2005 - 09:01:54 EST

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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Wed Dec 07 09:10:09 2005

Date: Wed 07 Dec 2005 - 09:01:54 EST

Good point. Probably not for any subsequent use in R. But, I work in an
org that uses SAS, HLM, SPSS, among others. As a part of our control
processes at times we replicate analyses in different software programs.
For instance, we will replicate lmer functions using HLM. But, HLM
requires a matrix of dummy variables. So, I have used R to create this
matrix for use in another software package that does need it.

-----Original Message-----

From: r-help-bounces@stat.math.ethz.ch

[mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of Berton Gunter
Sent: Tuesday, December 06, 2005 4:27 PM
To: 'Liaw, Andy'; 'Charles H. Franklin'; r-help@stat.math.ethz.ch
Subject: Re: [R] Matrix of dummy variables from a factor

But note: There are (almost?) no situations in R where the dummy variables coding is needed. The coding is (almost?) always handled properly by the modeling functions themselves.

- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA

"The business of the statistician is to catalyze the scientific learning process." - George E. P. Box

> -----Original Message-----

*> From: r-help-bounces@stat.math.ethz.ch
**> [mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of Liaw, Andy
**> Sent: Tuesday, December 06, 2005 12:30 PM
**> To: 'Charles H. Franklin'; r-help@stat.math.ethz.ch
**> Subject: Re: [R] Matrix of dummy variables from a factor
**>
**> See ?model.matrix.
**>
**> HTH,
**> Andy
**>
**> From: Charles H. Franklin
**> >
**> > What is a simple way to convert a factor into a matrix of dummy
**> > variables?
**> >
**> > fm<-lm(y~f)
**> >
**> > where f is a factor takes care of this in the estimation.
**> I'd like to
**> > save the result of expanding f into a matrix for later use.
**> >
**> > Thanks.
**> >
**> > Charles
**> >
**> > --
**> >
**> >
**> > Charles H. Franklin
**> > Professor, Political Science
**> > University of Wisconsin, Madison
**> > franklin@polisci.wisc.edu
**> > chfrankl@wisc.edu
**> > 608-263-2022 (voice)
**> > 608-265-2663 (fax)
**> >
**> > ______________________________________________
**> > 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
**> >
**> >
**>
**> ______________________________________________
**> 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
*

>

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide!

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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 Received on Wed Dec 07 09:10:09 2005

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