These are my questions: 1. For example, if this is my code:
>RegModel = lm(glucose~sex+BMI+height+weight+education+ses,weight=w_without_non_response) >summary(RegModel) >step(RegModel, direction ="backward",scope=list(lower=?,upper=?)) and I want the sex and height variables to be fixed, but the rest of the variables to go into the backward analysis, how should I write the scope function? 2.How can I add an alpha level to the step function as a criterion for the backward regression analysis? Thank you :) -- View this message in context: http://r.789695.n4.nabble.com/Stepwise-analysis-with-fixed-variables-tp4650015p4650280.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list 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.
