John Fox <jfox <at> mcmaster.ca> writes: > > Dear Kirk, > > Actually, co2 isn't a data frame but rather a "ts" (timeseries) object. A > nice thing about R is that you can query and examine objects: > > > class(co2) > [1] "ts" [...]
Yes. And with > frequency(co2) [1] 12 One gets "the number of observations per unit of time". When one sets the parameter "start" and "frequency" or "start" and "deltat" or "start" and "end" of a time-series, one can set the used values and that means that functions that use those values, also will be controlled by this. > start(co2) [1] 1959 1 > end(co2) [1] 1997 12 Rearranging by creaating a new ts-object with different timely parameters: > new_co2 <- ( ts( co2,frequency=1, start=1959) ) > start(new_co2) [1] 1959 1 > end(new_co2) [1] 2426 1 ... and the way back: > old_co2 <- ( ts( new_co2, frequency=12, start=1959) ) > start(old_co2) [1] 1959 1 > end(old_co2) [1] 1997 12 > using plot on those values will result in different plots. Why the mentioned test data is showed different wih summary, I don't see now, but I think the reason can also be found here! To have the test-data (or the way how it was constructed) could help in helping. Ciao, Oliver ______________________________________________ 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.
