meaning of lm( y~., data=mydat ), is it a language feature, is it documented, is it supported?
Hi John, This is indeed documented, but you'll have to look at the function formula(): ?formula Regarding the dot (.), here is the explanation from the help of formula(): "There are two special interpretations of . in a formula. The usual one is in the context of a data argument of model fitting functions and means ?all columns not otherwise in the formula?: see terms.formula. In the context of update.formula, only, it means ?what was previously in this part of the formula?." HTH, Ivan -- Ivan Calandra, PhD Scientific Mediator University of Reims Champagne-Ardenne GEGENAA - EA 3795 CREA - 2 esplanade Roland Garros 51100 Reims, France +33(0)3 26 77 36 89 ivan.calandra at univ-reims.fr -- https://www.researchgate.net/profile/Ivan_Calandra https://publons.com/author/705639/ Le 23/05/2016 ? 13:26, John Sorkin a ?crit :
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.
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