Hi Mike, >> I was at a loss to understand the use of "/" until I looked in "An >> Introduction [!] to R," >> where I found the explanation.
I am not with you on the [!], because the information is basically where you are "complaining" that it isn't, viz in your face --- i.e. in the introductory document ---, but the operator surely deserves a mention in ?formula. So on that score I agree with you. Best, Mark. Mike Prager wrote: > > In working through material on p.272 of MASS (4th ed.), I came > across the following model formula: > > pet1.lm <- lm(Y ~ No/EP - 1, Petrol) > > I was at a loss to understand the use of "/" until I looked in > "An Introduction [!] to R," where I found the explanation. > > My request is that more complete material on model formulae be > lifted from "Introduction to R" (or elsewhere) and put into the > main online help files. There are other useful notations that > may not be well known. Since formulae are not limited to any > particular function, perhaps an entry could be made under > "Formula". > > More justification: > > The help for "lm" does not explain this notation, nor did I find > a cross-reference to anything useful there. The R Reference > Manual seems to explain functions only. The R Language > Definition has no index entry for "formula" or "model formulae". > > Looking to print, neither the section on "model formula" on p.56 > of MASS nor the section surrounding the above example explains > the notation, nor could I find it in Dalgaard's book, nor in > Maindonald and Braun. > > This seems too nice a feature to keep hidden in plain sight. > > -- > Mike Prager, NOAA, Beaufort, NC > * Opinions expressed are personal and not represented otherwise. > * Any use of tradenames does not constitute a NOAA endorsement. > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > > -- View this message in context: http://www.nabble.com/Request%3A-Documentation-of-formulae-tp17567491p17568035.html Sent from the R devel mailing list archive at Nabble.com. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
