On Mon, 23 Jun 2003, Murad Nayal wrote: > - what is the correct way to -remove- a component from a list. this > seems to do the trick: list[[1]] = NULL, however, you'd think this > should simply attach a NULL object at the first component position?
This is in the FAQ, section 3.3.3, and is an S/R difference that catches people quite often. It's related to the difference between [] and [[]]. Generally you will find that it is better to program by generating whole lists with lapply() or to copy lists retaining what you want (which does not copy the components, in general, and so is cheap). As for your comments on books: `S Programming' does discuss the design of classes (both informal and formal), the main data sructures in R. As others have said, the Green Book (Chambers, 1998) is by not means out of date, except in the sense that the precise langage it describes has never been available: it is not a description of any version of S-PLUS nor R. Generally, though, you need to make sure you have at your fingertips the resources which come with R: the various manuals (including R-lang) and the on-line help. For example, I have just spend several days documenting in the help pages exactly how subscripting of data frames works (and correcting dozens of anomalies and bugs). -- 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