search for: nconst

...was constructed in. g<-lm(days~city,data=const) Some of the sites in const have not yet been completed, and therefore they have days==NA. I want to predict how many days these sites will take to complete (I've simplified the above discussion to remove many of the other factors involved.) nconst<-subset(const,is.na(const$days)) x<-predict(g,nconst) Error in model.frame.default(object, data, xlev = xlev) : factor city has new level(s) ALBANY This is because we haven't yet completed a site in Albany. If I just had one to worry about I could easily fix it (choose a nearby m...