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|RE: nlssystemfit using SUR method [ reply ]|
By: Arne Henningsen on 2014-09-14 06:59
I think that nlsystemfit() can estimate your model only if you assume a linear probability model for the survival probability model. Please also read the FAQ at systemfit's website:
I think that you need to derive the log-likelihood function (and preferably also its first derivatives) and maximise this function, e.g. with packages/function maxLik.
|nlssystemfit using SUR method [ reply ]|
By: Francisco Goes on 2014-08-31 10:39
For my master thesis I have fitted an individual tree diameter growth model and a survival probability model separately using R, but I was told that simultaneous estimation of these two models would minimize overall errors and provide a variance-covariance matrix as a whole.
In that respect, can you please tell me if I can do it with nlssystemfit using SUR (seemingly unrelated regression) method? If not, how can I do it in R?
My equations are:
- tree diameter growth model
- survival probability model mortal_final<-glm(sobrev~Verao+alto_fuste:puro+IC1arv+G1+Perc_G_ec1,family=binomial)