# Variance-Covariance Matrix in glm

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This is a small function Venables and Ripley provide in their MASS book. You don’t need it anymore because vcov() has a method for the glm class. However, it is useful to see how to extract bits from a fitted model object.**Quantitative Ecology**, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

vcov.glm<-function(obj){ #return the variance-covariance matrix of a glm object #from p. 188 in Venables and Ripley. 2002. #Modern Applied Statistics With S. Springer. New York. so <- summary(obj,corr=F) so$dispersion * so$cov.unscaled }

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