[R] Matrix of dummy variables from a factor

Andrew Robinson A.Robinson at ms.unimelb.edu.au
Wed Dec 7 02:47:37 CET 2005


how about when making predictions of contrasts using, for example,
estimable() from the gmodels package?  I find it very useful.


> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Berton Gunter
> Sent: Wednesday, 7 December 2005 8:27 AM
> To: 'Liaw, Andy'; 'Charles H. Franklin'; r-help at 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.
> Question: Can someone provide a "straightforward" example where the
> dummy
> variable coding **is** explicitly needed?
> -- 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

Andrew Robinson
Senior Lecturer in Statistics                       Tel: +61-3-8344-9763
Department of Mathematics and Statistics            Fax: +61-3-8344-4599
University of Melbourne, VIC 3010 Australia
Email: a.robinson at ms.unimelb.edu.au    Website: http://www.ms.unimelb.edu.au

More information about the R-help mailing list