look at
?factor
?formula
?data.frame
I hope it helps.
Best,
Dimitris
----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
http://www.student.kuleuven.be/~m0390867/dimitris.htm
Quoting Tim Sippel <tsippel at gmail.com>:
> I've a set of data to run a GLM on and am having trouble defining the
> categorical variables. For example, one of my variables is Year (ie. 1998,
> 1999). How do I define those years as factors/categorical variables?
>
> Cheers,
>
> Tim
>
> [[alternative HTML version deleted]]
>
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