Jeff, R has 'environments' as a general mechanism to pass around objects by reference. However, that does not help with most functions like 'apply' which take arguments other than environments. > I'm familiar with FF and BigMemory, but are there any packages/tricks> which > allow for passing such objects by reference without having to code> in C? With ff (and I assume with bigmemory as well) you can pass around objects by reference without C-coding.To be more precise with regard to ff: atomic ff objects have 'hybrid copying semantics', which means that two references to an ff object will share the data and SOME features (like the 'length') while OTHER features (like 'dim') are copied on modify (see 'vt' for an powerful application of this concept). You might want to have a look at 'ffapply' and friends and at 'chunk'.
HTH Jens Oehlschlägel ______________________________________________ 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.