I have found a similar problem when constructing formulae and passing them to glmmPQL. My solution was to use do.call(glmmPQL,...). See ?do.call.
HTH, Simon. pencer Graves wrote: > Please try again after upgrading to the versions of R and MASS. > > If you still have a problem, PLEASE do read the posting guide! > "www.R-project.org/posting-guide.html" before you submit another post. > Most of the people who donate their time to answer questions on this > listserve are more likely to answer a question if it is simple and > completely self contained -- including a very brief toy example that > they can copy from an email into R and reproduce the problem. If they > can't do that, they are less likely to understand your question and > therefore less likely to produce a useful answer -- and less likely to > bother to even read carefully your question. > > hope this helps, > spencer graves > > rsubcriber wrote: > > >> Dear all, >> >> for a cross-validation I have to use predict.glmmPQL() , where the >> formula of >> the corresponding glmmPQL call is not given explicitly, but constructed >> using as.formula. >> However, this does not work as expected: >> >> x1<-rnorm(100); x2<-rbinom(100,3,0.5); y<-rpois(100,2) >> mydata<-data.frame(x1,x2,y) >> >> library(MASS) >> # works as expected >> model1<-glmmPQL(y~x1, ~1 | factor(x2), family=poisson, data=mydata) >> predict(model1, newdata=mydata, type="response") >> >> f<-as.formula(paste("y", "~","x1")) >> # predict does not work: >> # Error in mCall[["fixed"]][-2] : object is not subsettable >> model2<-glmmPQL(f, ~1 | factor(x2), family=poisson, data=mydata) >> predict(model2, newdata=mydata, type="response") >> >> Has anyone an idea what goes wrong? >> I am using R 2.0.1 under Windows 2000. >> >> Thanks, >> Anneke >> >> ______________________________________________ >> R-help@stat.math.ethz.ch mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >> > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > > -- Simon Blomberg, B.Sc.(Hons.), Ph.D, M.App.Stat. Centre for Resource and Environmental Studies The Australian National University Canberra ACT 0200 Australia T: +61 2 6125 7800 email: Simon.Blomberg_at_anu.edu.au F: +61 2 6125 0757 CRICOS Provider # 00120C ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html