From: Adrian Baddeley (adrian@maths.uwa.edu.au)
Date: Wed 01 Aug 2001 - 13:35:41 EST
Message-id: <200108010335.LAA10032@zootje.maths.uwa.edu.au>
A question about the inner workings of glm() and dpois():
Suppose I call
glm(y ~ x, family=poisson, weights = w)
where y contains NON-INTEGER (but still nonnegative) values.
(a) Does glm() still correctly maximise
the weighted Poisson loglikelihood ?
(i.e. the function given by the same formal expression as the
weighted loglikelihood of independent Poisson variables Y_i
except that the y_i are now nonnegative real numbers)
(b) is this likely to change in future versions of R?
In R version 1.3.0, glm() gives a warning that the responses are not integers.
This seems to originate from dpois() which is used to evaluate the deviance
of the fitted model. In R versions prior to 1.3 it seemed to work
without complaint. So ..
(c) what is the recommended way to suppress the warning from
dpois() that the responses are not integers ?
Ideally I would like dpois() to accept noninteger responses and
evaluate using the gamma function..
thanks
---- Adrian Baddeley, Mathematics & Statistics, University of Western Australia <http://maths.uwa.edu.au/~adrian/>-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
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