On Tue, 10 Aug 2004, Martin Maechler wrote: > >>>>> "BDR" == Prof Brian Ripley <[EMAIL PROTECTED]> > >>>>> on Tue, 10 Aug 2004 05:47:28 +0100 (BST) writes: > > BDR> On Tue, 10 Aug 2004, Ross Ihaka wrote: > >> Rob Hyndman wrote: > >> > When part of a time series is extracted, the time series component is > >> > lost. e.g., > >> > x <- ts(1:10) > >> > x[1:4] > >> > > >> > It would be nice if there was a subsetting function [.ts to avoid this > >> > problem. However, it is beyond my R-coding ability to produce such a > >> > thing. Is someone willing to do it? > > BDR> There is a [.ts, in src/library/stats/R/ts.R, and it is documented > BDR> (?"[.ts"). > > >> Have you had a look at "window"? The problem with "[" > >> its that it can produce non-contiguous sets of values. > > BDR> Yes. > > indeed. window() is what we have been advocation for a long > time now ... (but see below). > > BDR> If you look in the sources for [.ts you will see, > BDR> commented, the code that was once there to handle cases > BDR> where the index was evenly spaced. But it was removed > BDR> long ago in favour of window(). I tried to consult the > BDR> logs, but it seems that in the shift from CVS to SVN > BDR> recently I can't get at them. I think the rationale > BDR> was that x[ind] should always produce an object of the > BDR> same class. > > well, that can't have been the only rationale since now > x[ind] is *not* of the same class - when the "ts" property is > lost in any case.
`always of the same class' : for all (non-trivial) values of ind. -- 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://stat.ethz.ch/mailman/listinfo/r-devel
