On Thu, 13 May 2004, Paul Johnson wrote: > > I still don't quite understand your point about the reason that coxph > crashes. Why does the difference of scale between the variables cause > trouble?
Because exp(beta*x) is very, very, large for many values of beta when x is that large. If exp(beta*x) ever becomes Inf the computations will break down. A better approach than scaling the x would be to update the step-halving code to handle infinities, because scaling doesn't necessarily fix the problem (though it does here), and has possible bad effects in masking a singular design matrix (as Peter Dalgaard pointed out). -thomas ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html