Using David's examples: do.call(stack, lapply(obs, get))
On Tue, Nov 16, 2010 at 4:04 PM, Kevin Ummel <kevinum...@gmail.com> wrote: > Sorry, I shouldn't have used 'sum' as an example; I am looking for a > solution in the case of functions that do not result in simple vectors or > matrices. > > The "real-world" example is something like the following using the 'raster' > package, though (I think) any command producing an S4 object could be a > candidate: > > r1 <- raster(system.file("external/test.grd", package="raster"))*1 > r2 <- raster(system.file("external/test.grd", package="raster"))*2 > > obs=objects(pattern=glob2rx("r?")) > > #Would like to generate the equivalent of... > > stack(r1,r2) > > ...using a variation of obs as an argument to 'stack' (potentially very > long). > > Cheers, > Kevin > > > On Nov 16, 2010, at 5:07 PM, David Winsemius wrote: > > > > > On Nov 16, 2010, at 10:34 AM, Kevin Ummel wrote: > > > >> A bit embarrassed to post this seemingly trivial question, but I can't > find anything in the archive that's quite relevant: > >> > >> a1=1 > >> a2=2 > >> > >> obs=objects(pattern=glob2rx("a?")) > >> > >> I want to utilize 'obs' as a function argument to produce something > like: > >> > >> sum(a1,a2) > >> > > > > ?get > > > sum(sapply(obs, get)) > > [1] 3 > > > > > >> Obviously, sum(obs) doesn't work, but I've tried variations of 'eval', > 'parse', 'mget', and 'noquote' without success. What am I missing? > >> > >> Thanks, > >> Kevin > >> > > -- > > David Winsemius, MD > > West Hartford, CT > > > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]
______________________________________________ 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.