R help - Jun 2004 - strucchange-esque inference for glms ?

hello R-world,

according to the strucchange package .pdf, "all procedures in this package
are
concerned with testing or assessing deviations from stability in the classical 
linear regression model."

i'd like to test/assess deviations from stability in the Poisson model.

is there a way to modify the strucchange package to suit my purposes, or should 
i use be using another package,   or is this a tough nut to crack? :)

my application is detecting the onset of a flu outbreak as new daily data 
trickles in from each morning from local hospitals.  seems to me like the same 
sort of inferential goal that strucchange refers to as "monitoring of 
structural change."

thank you in advance.
cheers,

alexis

Alexis:
> according to the strucchange package .pdf, "all procedures in this
> package are concerned with testing or assessing deviations from
> stability in the classical linear regression model."
>
> i'd like to test/assess deviations from stability in the Poisson
> model.
> 
> is there a way to modify the strucchange package to suit my purposes,
> or should i use be using another package,   or is this a tough nut to
> crack? :)
As of version 1.2-0 strucchange supports tests for parameter
instability in much more general models including GLMs. A simple example
would be

R> library(strucchange)
R> data(BostonHomicide)
R> mcus <- gefp(homicides ~ population, family = poisson, fit = glm,
                data = BostonHomicide, vcov = kernHAC)
R> plot(mcus)
R> sctest(mcus)

See our technical report "Generalized M-fluctuation tests for Parameter
Instability" (linked from my web page) for the theory behind it.
> my application is detecting the onset of a flu outbreak as new daily
> data trickles in from each morning from local hospitals.  seems to me
> like the same sort of inferential goal that strucchange refers to as
> "monitoring of structural change."
In principile the theory established in the report above could also be
applied to monitoring, but I have neither worked the theory out nor
implemented a function which could handle monitoring in GLMs. But you
can contact me off-list if you are interested in this.

Best,
Achim