labbig <lkaimaka <at> windowslive.com> writes: > > i am trying to run stepwise regression for two models(lower,upper), > family=gamma > and i get the same error despite the models i use. > > Error in UseMethod("extractAIC") : > no applicable method for 'extractAIC' applied to an object of class > "formula" > In addition: Warning message: > In nobs.default(object, use.fallback = TRUE) : > no 'nobs' method is available >
A reproducible example would definitely help. The "no 'nobs' method is available" warning is a clue that you may be using an older version of R (I believe 'nobs' was introduced in version 2.13). If you possibly can, update to the latest version of R and post a reproducible example. Ben Bolker ______________________________________________ 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.