Displaying 1 result from an estimated 1 matches for "tp3902173p3915009".
2011 Oct 13
2
GLM and Neg. Binomial models
Hi userRs!
I am trying to fit some GLM-poisson and neg.binomial. The neg. Binomial
model is to account for over-dispersion.
When I fit the poisson model i get:
(Dispersion parameter for poisson family taken to be 1)
However, if I estimate the dispersion coefficient by means of:
sum(residuals(fit,type="pearson")^2)/fit$df.res
I obtained 2.4. This is theory means over-dispersion since