meaning of lm( y~., data=mydat ), is it a language feature, is it documented, is it supported?
John Sorkin <JSorkin <at> grecc.umaryland.edu> writes:
The syntax mydat <- data.frame( y,x ) fit1 <- lm( y~., data=mydat ) appears to perform a multivariable regression of y on
every non-y variable in the data frame mydat. I can not
find this syntax (y~.) in R documentation. Is y~.
a supported feature of the R language? Where can I find it
documented? I would hate to write code that
is dependent on a non-supported, non-documented language feature.
Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of
Medicine Division of Gerontology and Geriatric Medicine
Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913
How about section 11.5 of An Introduction to R?
Kenneth Knoblauch Inserm U1208 Stem-cell and Brain Research Institute 18 avenue du Doyen L?pine 69500 Bron France tel: +33 (0)4 72 91 34 77 fax: +33 (0)4 72 91 34 61 portable: +33 (0)6 84 10 64 10 http://www.sbri.fr/members/kenneth-knoblauch.html