Hi Josh, I think, m <- lm(mpg ~ factor(cyl)+I(mpg^2), data = mtcars) nd<-get_all_vars(m,data=mtcars)
is what you are after. cheers. Am 17.08.2011 04:27, schrieb Joshua Wiley: > Hi All, > > I am writing a function to predict values based on a model. It works > fine as long as the formula just uses regular variable names. I am > having a problem when the variables are wrapped with a function call. > For example: > > m <- lm(mpg ~ factor(cyl), data = mtcars) > ## I get the column names using > as.character(attr(terms(m), "variables"))[-1L] > ## which gives the same column names as in > # m$model > > predict(m, m$model) # returns an error that 'cyl' is not found > > Is there an easy way to get just the variable names or a template data > frame that I can populate with my own values from a model object? My > best idea right now is to use a regular expression to strip away > everything before and after (). This would break down for things like > I(cyl^2), though. > > Any ideas or thoughts would be welcome. > > Thanks, > > Josh > > -- Eik Vettorazzi Institut für Medizinische Biometrie und Epidemiologie Universitätsklinikum Hamburg-Eppendorf Martinistr. 52 20246 Hamburg T ++49/40/7410-58243 F ++49/40/7410-57790 ______________________________________________ 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.
