Martin Maechler
2015-May-18 12:14 UTC
[Rd] \alias{} --> rather \concept{} for conceptual "links" to help pages
>From R-help, subject "Variable number of loops"I've opened a new thread, moving from R-help to R-devel ..>>>>> Jim Lemon <drjimlemon at 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.berton at 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.wray at 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.berton at 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 >>>> [...............]
Hervé Pagès
2015-May-18 20:31 UTC
[Rd] \alias{} --> rather \concept{} for conceptual "links" to help pages
Hi Martin, On 05/18/2015 05:14 AM, Martin Maechler wrote:> From R-help, subject "Variable number of loops" > I've opened a new thread, moving from R-help to R-devel .. > >>>>>> Jim Lemon <drjimlemon at 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'.It seems to me that Jim was maybe suggesting to define an alias for the expand.grid function i.e. something like: permute.elements <- expand.grid or combine.elements <- expand.grid as a way to address the "less than obvious naming of the expand.grid function". But maybe I misunderstood... Cheers, H.> > 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.berton at 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.wray at 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.berton at 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 at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel >-- Herv? Pag?s Program in Computational Biology Division of Public Health Sciences Fred Hutchinson Cancer Research Center 1100 Fairview Ave. N, M1-B514 P.O. Box 19024 Seattle, WA 98109-1024 E-mail: hpages at fredhutch.org Phone: (206) 667-5791 Fax: (206) 667-1319