[R] Power to detect change (poisson)

[Good, Norman]

Hi All (first timer here, be gentle!!)

I'm trying to extract the residual variance out of a glm with poisson data
to
conduct power and sample size to detect a change over years.
I have equal reps within year (for now).

Is the residual variance just the grand mean of the original count data, or
something trickier?

glm.Male_glm(M~year*strata,family=poisson,offset=dur)

 levels(year)
[1] "2000" "2001"
> levels(strata)
[1] "0-4"   "4.1-8"    "12.1-16" "8.1-12" 





Norm Good

Fisheries Biologist (Mathematician)
Southern Fisheries Centre
PO Box 76, Deception Bay Q 4508
telephone 3817 9588, fascimile 3817 9555




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