On Oct 29, 2013, at 4:38 AM, rm wrote: > Any ideas would be much appreciated; I suspect that this problem of > constructing the dummies applies not only to function coxph but to other > regression models in R as well. Effectively, my question is how to better > control for which dummies and interactions to include in the model and which > not. > > The following code shows a workaround. It works here reasonably well since x > has only two levels, but if x has more levels, constructing the dummies > manually for each level and keeping track of each of them becomes very > difficult. > > > > A weird thing is that if onle replace line 4 with > >
You should go to the R-help Archive to see what the vast majority of readers of this mailing list are seeing. https://stat.ethz.ch/pipermail/r-help/2013-October/362203.html > > the problem reappears. Any idea why? A numeric (0 or 1) variable produces > different interactions than a logical variable (FALSE or TRUE). > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/coxph-how-to-define-interaction-terms-tp4679162p4679249.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 you should read both the fine posting guide and the messages that Nabble suppresses in its effort to masquerade as Rhelp. "and provide commented, minimal, self-contained, reproducible code." -- David Winsemius Alameda, CA, USA ______________________________________________ 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.
