[R] From THE R BOOK -> Warning: In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!

[Corrado]

Dear Ruben

I am afraid not .... the paragraph's title is a bit of a give away:

Proportion Data and Binomial Errors

The sentence reads:

" .... are dealt with by using a generalised linear model with a 
binomial error structure".

with the example:

glm(y~x,family=binomial)

You can check at page 514/515.

Rubén Roa wrote:
> -----Mensaje original-----
> De: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] En nombre de Corrado
> Enviado el: martes, 30 de marzo de 2010 16:52
> Para: r-help at r-project.org
> Asunto: [R] From THE R BOOK -> Warning: In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!
>
> 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: ct529 at york.ac.uk