try : my_formula = as.formula(paste("y~",xxx)) lm(my_formula) note that you can play with substr in paste to change your formula > paste("y~",substr(xxx,1,5)) [1] "y~ x1+x2" > paste("y~",substr(xxx,4,8)) [1] "y~ x2+x3"
furthermore, with 10 predictors x1 x2 ...x10 for instence, you can create 2 array of indice where to start and end the substr and do it in a loop for multi fit... best, yves > On 11/18/05, Juni Joshi <[EMAIL PROTECTED]> wrote: > > > > I need to fit a number of models with different number of predictors > > in each model. Say for example, I have three predictors: x1, x2, x3 > > and I want to fit three models: > > > > lm(y~x1+x2) > > lm(y~x2+x3) > > lm(y~x1+x2+x3) > > > > Instead of typing all models, what I want is to create a variable > > which can take the right hand side of the models. I tried this with > > paste function. > > > > xxx <- paste("x1","x2",sep=+) for the first > > xxx <- paste("x2","x3", sep = +) for the second > > xxx <- paste("x1","x2","x2", sep = +) for the third and then fit a > > single model > > > > lm(y~xxx) > > > > It did not work. Please suggest how to do it. > > > > Thanks. > > > > Jun > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html