>From R-help, subject "Variable number of loops" I've opened a new thread, moving from R-help to R-devel ..
>>>>> Jim Lemon <drjimle...@gmail.com> >>>>> on Sun, 17 May 2015 09:19:06 +1000 writes: > Hi all, Given the number of help requests that involve > permutations/combinations, and the less than obvious > naming of the expand.grid function, perhaps adding an > alias such as "permute.elements" or "combine.elements" > might ease the tasks of both searchers and those offering > help. Neither of the above names appear to be used at > present. > Jim Using \alias{} is not a very good thing here, since as you know they are *key*s that must remain unique if possible and they can be linked to -- which I think would not be helpful for 'expand.grid'. Rather, for quite a few years now, we have had \concept{} for adding "search keywords", i.e., things that help.search() and hence ??<topic> will find. The other advantage of \concept{} is that you can use short phrases, i.e., \concept{all variable combinations} would be possible here. (Better wording proposals for this specific case are welcome! -- maybe privately). Martin Maechler, ETH Zurich > On Sun, May 17, 2015 at 5:54 AM, Bert Gunter > <gunter.ber...@gene.com> wrote: >> 1. Please always reply to the list unless there is a >> compelling reason to keep the discussion private. You >> will have a better chance of getting something useful >> that way. >> >> 2. I don't know what you mean by "I don't have a fixed >> number of variables." You have to specify at least the >> number of variables and how many levels each has in order >> to work out what you requested, which is **NOT** the >> number of permutations but the number of combinations >> AFAICS, which is exactly what expand.grid will give you. >> >> 3. Maybe what you're looking for is the ... arguments in >> function calls, which would be used along the lines of: >> >> myfun <- function( x,y,...) { ## some code combs <- >> expand.grid(...) ## some more code } >> >> Any good R tutorial will tell you about this if this is >> unfamiliar. >> >> 4. Another possibility might be to deliver a list of >> named variables as an argument and then use do.call, e.g. >> >> myfun <- (x,y, alist) { ## some code combs <- >> do.call(expand.grid, alist) ## some more code } >> >> ?do.call and/or a tutorial for details. >> >> 5. Otherwise, maybe someone else can figure out what >> you're looking for. >> >> Cheers, Bert >> >> >> >> Bert Gunter Genentech Nonclinical Biostatistics (650) >> 467-7374 >> >> "Data is not information. Information is not >> knowledge. And knowledge is certainly not wisdom." >> Clifford Stoll >> >> >> >> >> On Sat, May 16, 2015 at 11:16 AM, WRAY NICHOLAS >> <nicholas.w...@ntlworld.com> wrote: >>> I might be but doesn't expand.grid need a defined and >>> listed number of inputs? The problem I'm having is that >>> the number of variables is not fixed, so I'm not sure >>> whether I can reference the variable number of variables >>> by using a vector -- haven't had time to try yet But >>> thanks anyway Nick Wray >>> >>> On 16 May 2015 at 14:28, Bert Gunter >>> <gunter.ber...@gene.com> wrote: >>>> >>>> Are you trying to reinvent ?expand.grid ? >>>> >>>> -- Bert >>>> >>>> Bert Gunter Genentech Nonclinical Biostatistics (650) >>>> 467-7374 >>>> >>>> "Data is not information. Information is not >>>> knowledge. And knowledge is certainly not wisdom." >>>> Clifford Stoll >>>> [...............] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel