It's a bug in summary.aareg which no one found until now. What's wrong: If dfbeta=TRUE then there is a second estimate of variance calculated, labeled as test.var2. If maxtime is set, then both estimates of variance need to be recalculated by the summary routine. An incorrect if-then-else flow led it to look for test.var2 when it wasn't relevant. My test cases with maxtime also happened to have dfbeta=TRUE. Short term solution: set dfbeta=TRUE. A bit more computation time though. Long term: I'll fix it, and a new version of survival will one day appear. (With 200+ packages that depend on survival, new releases now require a lot of checking. No overnight fixes). Terry T
On 10/05/2012 05:00 AM, r-help-request at r-project.org wrote:
Hi all, I've ventured into the world of nonparametric survival and I would like to use the "maxtime" option for printing and plotting my aareg fit. However, my fit does not have "test.var2" and this stops the print and plot when adding a maxtime. My code is as follows: Response<-Surv(Time,Event) Model<-aareg(Response~Factor1*Factor2) Model2<-aareg(Response~Factor1+Factor2) #Just did this to see if the interaction term had anything to do with it Model, print(Model), summary(Model), and plot(Model) seem to work fine, but as soon as I try summary/print/plot(Model, maxtime=400) it tells me that test.var2 is not found and when I look at summary(Model), there is indeed a NULL under test.var2. Anyone know why it doesn't include test.var2? Is this a compatibility problem? I'm using R version 2.13 (I know it's quite old, but updating is a pain when you don't have admin rights to your computer) and just updated the survival package (no warning messages). Any input would be much appreciated. Cheers, Freya