In a Binomial GLM, typically y is a factor with two levels (indicating success/failure) instead of a numeric vector on [0, 1]. Perhaps the description in the book is not so clear. You should interpret "data on proportions" as the observations from a Binomial distribution (rather than we observed some proportion data which fell in [0,1]). E.g.
y=rbinom(10, size = 1, prob = .3); x=rnorm(y) # or y = factor(y) glm(y~x, family = binomial) Regards, Yihui -- Yihui Xie <xieyi...@gmail.com> Phone: 515-294-6609 Web: http://yihui.name Department of Statistics, Iowa State University 3211 Snedecor Hall, Ames, IA On Tue, Mar 30, 2010 at 9:51 AM, Corrado <ct...@york.ac.uk> wrote: > Dear friends, > > I am testing glm as at page 514/515 of THE R BOOK by M.Crawley, that is on > proportion data. > > I use glm(y~x1+,family=binomial) > > y is a proportion in (0,1), and x is a real number. > > I get the error: > > In eval(expr, envir, enclos) : non-integer #successes in a binomial glm! > > But that is exactly what was suggested in the book, where there is no > mention of a similar warning. Where am I going wrong? > > Here is the output: > >> glm(response.prepared~x,data=dddd,family=binomial) > > Call: glm(formula = response.prepared ~ x, family = binomial, data = dddd) > > Coefficients: > (Intercept) x -0.3603 0.4480 > Degrees of Freedom: 510554 Total (i.e. Null); 510553 Residual > Null Deviance: 24420 > Residual Deviance: 23240 AIC: 700700 > Warning message: > In eval(expr, envir, enclos) : non-integer #successes in a binomial glm! >> > > > > Regards > -- > > Corrado Topi > PhD Researcher > Global Climate Change and Biodiversity > Area 18,Department of Biology > University of York, York, YO10 5YW, UK > Phone: + 44 (0) 1904 328645, E-mail: ct...@york.ac.uk > > ______________________________________________ > 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. > ______________________________________________ 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.
