Re: [R] logistic regression model with non-integer weights

2006-04-16 Thread Frank E Harrell Jr
Ramón Casero Cañas wrote: > Frank E Harrell Jr wrote: > >>This makes me think you are trying to go against maximum likelihood to >>optimize an improper criterion. Forcing a single cutpoint to be chosen >>seems to be at the heart of your problem. There's nothing wrong with >>using probabilities a

Re: [R] logistic regression model with non-integer weights

2006-04-16 Thread Ramón Casero Cañas
Frank E Harrell Jr wrote: > > This makes me think you are trying to go against maximum likelihood to > optimize an improper criterion. Forcing a single cutpoint to be chosen > seems to be at the heart of your problem. There's nothing wrong with > using probabilities and letting the utility posse

Re: [R] logistic regression model with non-integer weights

2006-04-16 Thread Frank E Harrell Jr
Ramón Casero Cañas wrote: > Michael Dewey wrote: > >>At 17:12 09/04/06, Ramón Casero Cañas wrote: >> >>I am not sure what the problem you really want to solve is but it seems >>that >>a) abnormality is rare >>b) the logistic regression predicts it to be rare. >>If you want a prediction system wh

Re: [R] logistic regression model with non-integer weights

2006-04-16 Thread Rick Bilonick
On Sun, 2006-04-16 at 19:10 +0100, Ramón Casero Cañas wrote: > Thanks for your suggestions, Michael. It took me some time to figure out > how to do this in R (as trivial as it may be for others). Some comments > about what I've done follow, in case anyone is interested. > > The problem is a) abno

Re: [R] logistic regression model with non-integer weights

2006-04-16 Thread Ramón Casero Cañas
Michael Dewey wrote: > At 17:12 09/04/06, Ramón Casero Cañas wrote: > > I am not sure what the problem you really want to solve is but it seems > that > a) abnormality is rare > b) the logistic regression predicts it to be rare. > If you want a prediction system why not try different cut-offs (o

Re: [R] logistic regression model with non-integer weights

2006-04-12 Thread Michael Dewey
At 17:12 09/04/06, Ramón Casero Cañas wrote: I have not seen a reply to this so far apologies if I missed something. >When fitting a logistic regression model using weights I get the >following warning > > > data.model.w <- glm(ABN ~ TR, family=binomial(logit), weights=WEIGHT) >Warning message

[R] logistic regression model with non-integer weights

2006-04-09 Thread Ramón Casero Cañas
When fitting a logistic regression model using weights I get the following warning > data.model.w <- glm(ABN ~ TR, family=binomial(logit), weights=WEIGHT) Warning message: non-integer #successes in a binomial glm! in: eval(expr, envir, enclos) Details follow *** I have a binary dependent varia