On Mon, Nov 26, 2012 at 5:33 AM, Florian Weiler <fweile...@jhubc.it> wrote:
> Dear all, > > I am using the book "Generalized Linera Models and Extension" by Hardin and > Hilbe (second edition, 2007) at the moment. The authors suggest that > instead of OLS models, "the log link is generally used for response data > that take only positive values on the continuous scale". <snip> > specifying *family=gaussian(link="log") *I > am asked to provide starting values. When I set them all equal to zero, I > always get the message that the algorithm did not converge. Picking other > values the message is sometimes the same, but more often I get: > * > * > *Error in glm.fit(x = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, : > * > * NA/NaN/Inf in 'x' * > * > * > As I said, in STATA I can run these models without setting starting values > and without errors. I tried many different models, and different datasets, > And yet you've failed to provide even one of them together with your code as a reproducible example ... # This works without starting values: set.seed(2341) x <- rep(1:10,3) ; y <- jitter(rpois(30,5+x)) plot(x,y) (gausslog <- glm(y~x,family=gaussian(link='log'))) exp(coef(gausslog)) # This works only with starting values set.seed(2341) x <- rep(1:10,3) ; y <- jitter(rpois(30,x)) plot(x,y) ; summary(y) # yes,yes, some y <0, just trying to reproduce the error... (gausslog <- glm(y~x,family=gaussian(link='log'))) (gausslog <- glm(y~x,family=gaussian(link='log'),start=c(0,0))) # also set.seed(2341) x <- rep(1:10,3) ; y <- rnorm(30,0+0.1*x) plot(x,y) ; summary(y) (gausslog <- glm(y~x,family=gaussian(link='log'),start=c(0,0))) So really this is a non issue without the offending data set and code. but the problem is always the same (unless I only include one single > independent variable). Oh, more information... way to build up the suspense set.seed(2341) x <- rep(1:10,3) ; xx <- rep(seq(20,50,l=5),6) ; y <- rnorm(30,5+3*x-2*xx) (gausslog <- glm(y~x+xx,family=gaussian(link='log'),start=c(0,0,0))) No joy. Still fits. > Could anyone tell me why this is the case, or what I > do wrong, No > or why the suggested models from the book might not be > appropriate? I'd appreciate any help! > > Personally I don't care for reproducing some results from STATA and have no comment on the validity of the above but maybe someone in the list would have a better answer if you repost. > Best, > Florian > > Also this: > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.
