On Tue, 16 Sep 2003, Peter Whiting wrote: > On Tue, Sep 16, 2003 at 04:17:59PM -0400, Thomas W Blackwell wrote: > > Peter - > > > > Your subsequent email seems just right. You have to determine > > ahead of time which rows can be estimated. > > It seems that predict removes rows with insufficient information > (ie, if I replace "ALBANY" with NA and refactor everything works) > - I wonder why it doesn't exhibit the same behavior when it > encounters a new level - just eliminate the row and go on... > > Somewhat related: I had been assuming (incorrectly) > that length(x) would equal length(const$days) after > x<-predict(g,const) - this isn't the case if any of the rows of > const don't contain enough info for the model. Those rows are > eliminated - I'd have expected them to just be NAs in the result.
That depends on the setting of option na.action: the factory-fresh default is na.omit, which is what you are seeing. As from R 1.8.0 it will use a default of na.pass for predict.lm. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
