On Jun 29, 2012, at 23:56 , agittens wrote: > I fit a coxph model: > > coxphfit <- coxph(Surv(sampledLifetime, !sampledCensoredQ) ~ curpbc6 + > prevpbc6, sampledTimeSeries) > > Now I'm trying to predict the expected number of events using a new dataset. > The documentation suggests that > > coxPred <- predict(coxphfit, newdata = testTimeSeries, type="expected") > > will do what I want, but I get the error > > Error in model.frame.default(data = testTimeSeries, formula = > Surv(sampledLifetime, : > variable lengths differ (found for 'curpbc6') > > when I do this. The dataframes sampledTimeSeries and testTimeSeries were > constructed by taking rows from a larger dataframe, so they have the same > data. > > What am I doing incorrectly?
Most likely referring to a variable not in testTimeSeries. (I kind of suspect that unlike predict.lm, predict.coxph does not ignore the left hand side of formulas. Does testTimeSeries contain a sampledLifetime column?) -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.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.
