> For me better all the x variables (collectively), to have m% missing values.
I checked the mgcv documentation. Observations with (any) missing values are ignored. (i.e. The entire row, from your input data). "If there are missing values in the reponse or covariates of a GAM then the default is simply to use only the ‘complete cases’." I haven't checked the ISLR package. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.