[R] statistical prediction for glm()

[Martin Wegmann]

hello, 

I apologize that I poste this question again but I did not receive any replies 
on this topic and would like to know if the mail has been read over or if 
there is no method of statistical prediction computation for poisson errors 
in glm(). 

I am looking for a way to compute the model prediciton error of a glm() with 
poisson error family.
cv.glm() does not work. (it prompts values around 90.00)

A " not there isn't such a method" would be fine as well.

Thanks in advance, Martin