Hello Steve, On Thu, Jul 16, 2009 at 2:28 AM, S Ellison<s.elli...@lgc.co.uk> wrote: > Auto-updating sounds hard in R for a 'regular' data frame. You could > perhaps define an entirely new class of object and define data > entry/indexing methods so that, say, they sought functions in an > attribute defined as a list of lists of the form (target, source, fun) > and inserted the result of applying function fun to column name(s) > source into a column named target. But I've not tried it, and you'd have > to work out how to append, update and delete the functions as well as > work out all the possible entry/indexing operators in order to make sure > you caught all the possibilities for messing up. Sounds nasty. > Nasty indeed.
> Much simpler to write your row drop as something simple like > y.clean<-subset(y, y$bad|y$worse) > where $bad and $worse are your two 'drop me' flag columns. > An(other) efficient solution to the second part of the problem. Now for this specific case of flagging for removal I no longer need a third logical, and autoupdating; I can use all relevant variables in one call. I settled for the following syntax: > dim(tmp.obj) #original object [1] 35771 28 > dim(subset(tmp.obj, !tmp.obj$dupl.yr & !tmp.obj$unmat.yr)) #object > subsetted using the twocols [1] 35737 28 > dim(subset(tmp.obj, !tmp.obj$rm.yr)) #object subsetted using the third > logical [1] 35737 28 I needed to replace "|" with "&" to get this result. I'm also negating the logicals, since I have TRUE for "remove". Thank you Liviu ______________________________________________ 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.
