[R] glm: offset in poisson

[Juli G. Pausas]

R-users,

Can an offset term be included in a Poisson model? 
I get an error message when trying that:

>r3o <- glm(tax ~ areal + offset(o), family=poisson)
Error in (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  : 
        inner loop 1; can't correct step size
In addition: Warning message: 
Step size truncated due to divergence in: (if (is.empty.model(mt))
glm.fit.null else glm.fit)(x = X, y = Y,  

(this error message doesn't appear with family= gaussian)

Juli


********************
Juli G. Pausas
Centro de Estudios Ambientales del Mediterraneo (CEAM)
C/ C.R. Darwin 14
Parc Tecnologic,
46980 Paterna, Valencia, SPAIN
Tel: (+ 34) 96 131 8227
Fax: (+ 34) 96 131 8190
E-mail: juli at ceam.es
http://www.gva.es/ceam

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