On 16-Jul-07 13:28:50, Gabor Grothendieck wrote: > The formula attribute of the builtin CO2 dataset seems a bit strange: > >> formula(CO2) > Plant ~ Type + Treatment + conc + uptake > > What is one supposed to do with that? Certainly its not suitable > for input to lm and none of the examples in ?CO2 use the above.
I think one is supposed to ignore it! (Or maybe be inspired to write a mail to the list ... ). I couldn't find anything that looked like the above formula from str(CO2). But I did spot that the order of terms in the formula: Plant, Type, treatment, conc, uptake, is the same as the order of the "columns" in the dataframe. So I tried: D<-data.frame(x=(1:10),y=(1:10)) formula(D) x ~ y So, lo and behold, D has a formula! Or does it? Maybe if you give formula() a dataframe, it simply constructs one from the "columns". Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 16-Jul-07 Time: 14:57:28 ------------------------------ XFMail ------------------------------ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
