Hi Georgiana,

Take a look at the betareg package at
http://cran.r-project.org/web/packages/betareg/index.html

HTH,
Jorge.-


On Mon, Mar 19, 2012 at 10:05 AM, Georgiana May <> wrote:

> Hello,
> I want to determine the regression relationship between a proportion (y)
> and a continuous variable (x).
> Reading a number of sources (e.g. The R Book, Quick R,help), I believe I
> should be able to designate the model as:
>
> model<-glm(formula=proportion~x, family=binomial(link="logit"))
>
> this runs but gives me error messages:
> Warning message:
> In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!
>
> If I transform the proportion variable with log, it doesn't like that
> either (values not: 0<y<1)
>
> I understand that the binomial function concerns successes vs. failures and
> can use those raw data, but the R Book and other sources seem to suggest
> that proportion data are usable as well.  Not so?
>
> Thank you,
> Georgiana May
>
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