[R] Generic functions with models? 'predict', 'residuals', 'fitted', ...?

Hi WizaRds! I don't know if my understanding of models is screwed up or if there's a fundamental limitation to the way they are used in R. Here's what I'd like to do: create a model and then test data against that model using generics like 'predict' and 'residuals'. The problem is that generics

[R] plotting NAs

Hi WizaRds, (I've cross-posted to r-sig-finance because a lot of people there use 'zoo' objects). I'm trying to plot 2 time series lined up with par(mfrow=c(2,1)), so that the time index is the same for the two series. The data have monthly frequency. An example will illustrate: # data for t

[R] RODBC and Oracle

Hi WizaRds, I'm experiencing a problem connecting to an Oracle 10g database via RODBC (I'm getting this on Microsoft XP). The same SQL queries via PL/SQL Developer work just fine, but when I pump the query through sqlQuery in RODBC then I get a data frame back with 0 rows. I cut the query down

[R] Multivariate, multilevel regression?

Dear WizaRds, This is mostly a statistics question, but I'm figuring that R is the right solution (even before I start!) I have some bio data of heart rate versus time (rats taken from resting to maximal heart rate). I want to regress heart rate on time. The data have been normalized such that