[R] GLM weights for the Poisson family

David Winsemius dwinsemius at comcast.net
Tue Feb 4 21:43:53 CET 2014

On Feb 3, 2014, at 11:12 PM, IamRandom wrote:

> I am running a simple example of GLM.  If I include weights when family="poisson" then the weights are calculated iteratively and $weights and $prior.weights return different values.  The $prior.weights are what I supplied and $weights are the "posterior" weights of the IWLS.  If I include weights with family="gaussian" then the weights are static and $weights and $prior.weights return the same values; it seems to ignore IWLS algorithm procedure.

I don't think so. I think it's just starting where you specify and proceeding normally from there.

>  I really want the family="poisson" to behave like the family="gaussian" and use the static weights.  Thoughts?

I was under the impression there is no need to iterate for family="gaussian". If my understanding is correct only one "iteration" gets done.

Maybe you should say what you are trying to accomplish.


David Winsemius
Alameda, CA, USA

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