On May 23, 2014, at 2:04 PM, Adams, Jean wrote: > Roland, > > I did a google search for > R Error: inner loop 2; cannot correct step size > and found an old R-help message that suggests the glm() algorithm cannot > converge. > https://stat.ethz.ch/pipermail/r-help/2009-December/223142.html > > I get the same error message as you when I fit > glm(cbind(resp,nresp)~d+I(d^2)+I(d^3),data=test,family= > binomial(clog()))
Six redictor factor levels? With zeros at the extremes. Fitting to three parameters? > but no error message if I get rid of the last parameter > glm(cbind(resp,nresp)~d+I(d^2),data=test,family=binomial(clog())) I thought perhaps removing the correlation of d^2 and d^3 might help, but even using: ~ poly(d, 3) fails. If you remove the `clog()` call and use the canonical link, you get estimates with a warning (as one might expect with this data: Warning message: glm.fit: fitted probabilities numerically 0 or 1 occurred -- David. > > Hope this helps > > Jean > > > On Fri, May 23, 2014 at 7:13 AM, Roland Deutsch <roland.deut...@tuwien.ac.at >> wrote: > >> Dear R-help, >> >> during a simulation study using glm, I got the following error message >> for which I cannot determine the cause: >> >> Error: inner loop 2; cannot correct step size >> >> Below is the code for which this error occurred is >> >> clog<-function(){ >> linkfun<-function(mu) qexp(mu) >> linkinv<-function(eta) pmax(.Machine$double.eps,pexp(eta)) >> mu.eta<-function(eta) pmax(dexp(eta),.Machine$double.eps) >> valideta<-function(eta) all(eta>0) >> link<-"clog" >> >> >> structure(list(linkfun=linkfun,linkinv=linkinv,mu.eta=mu.eta,valideta=valideta,name="link"),class="link-glm") >> } >> >> test<-data.frame(d=c(0,0.04,0.2,0.6,2,4),resp=c(0,1,3,4,24,28),nresp=c(18,21,19,17,1,0)) >> glm(cbind(resp,nresp)~d+I(d^2)+I(d^3),data=test,family=binomial(clog())) >> >> Any help on why this error occurs and, more importantly, how I can >> filter data producing this error would be highly appreciated. >> >> Sincerely, >> Roland Deutsch David Winsemius Alameda, CA, USA ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.