I tried formula<-y~X1+X2+X3 update.formula(formula,.-NewRandomEffects~.)
and this runs without an error. So I still didn't get the point. You may also need to insulate your new response variable if you want to estimate a model with in fact only one response variable, which ist done by I() as in update.formula(formula,I(.-NewRandomEffects)~.) hrth. Rebecca Sela schrieb: > Update looks like the function I want to use, but it still isn't working, > possibly because I am doing something more complicated than my message > implied. > > What I want to do is subtract a vector of random effects (determined within > the function) from Y. I hoped that something like this: > tree <- rpart(update(formula,.-NewRandomEffects~.)) > would work, but I got the message > Error in update.default(formula, . - NewRandomEffects ~ .) : > need an object with call component > > I have considered creating a function that would subtract the random effect > from each Y individually, but there is no identifier on Y. > > Is there an obvious fix I'm missing? > > Thanks for your suggestions! > > Rebecca > > > > ----- Original Message ----- > From: "Eik Vettorazzi" <[EMAIL PROTECTED]> > To: "Rebecca Sela" <[EMAIL PROTECTED]> > Cc: r-help@r-project.org > Sent: Monday, October 1, 2007 11:34:13 AM (GMT-0500) America/New_York > Subject: Re: [R] Disentagling formulas > > maybe I didn't understand the problem, but you can do sth like > > formula<-y~X1+X2+X3 > lm(update.formula(formula,f(Y)~.)) > > maybe > ?all.vars > or > ?terms > will help you too. > > hth. > > > Rebecca Sela schrieb: > >> I am writing a program in which I would like to take in a formula, change >> the response (Y) variable into something else, and then pass the formula, >> with the new Y variable to another function. That is, I am starting with >> formula <- Y~X1+X2+X3 >> and I'd like to do something like >> Y <- formula$Y >> newY <- f(Y) >> lm(newY~X1+X2+X3) >> So far, it seems that my only option will be a very complicated sequence of >> steps involving match.call(). Is there a simpler way to change the response >> variable in a formula? >> >> Thanks in advance! >> >> Rebecca >> >> -- >> Rebecca Sela >> Statistics Department >> Stern School of Business >> New York University >> >> ______________________________________________ >> 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. >> >> > > > -- Eik Vettorazzi Institut für Medizinische Biometrie und Epidemiologie Universitätsklinikum Hamburg-Eppendorf Martinistr. 52 20246 Hamburg T ++49/40/42803-8243 F ++49/40/42803-7790 ______________________________________________ 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.
