I'd vote for it to stay. It could of course suprise someone who'd expect c(list(a=1), b=2, use.names = FALSE) to generate list(a=1, b=2, use.names=FALSE). On the upside, is the performance gain from using use.names=FALSE. Below benchmarks show that the combining of the names attributes themselves takes ~20-25 times longer than the combining of the integers themselves. Also, at no surprise, use.names=FALSE avoids some memory allocations.> options(digits = 2) > > a <- b <- c <- d <- 1:1e4 > names(c) <- c > names(d) <- d > > stats <- microbenchmark::microbenchmark(+ c(a, b, use.names=FALSE), + c(c, d, use.names=FALSE), + c(a, d, use.names=FALSE), + c(a, b, use.names=TRUE), + c(a, d, use.names=TRUE), + c(c, d, use.names=TRUE), + unit = "ms" + )> > statsUnit: milliseconds expr min lq mean median uq max neval c(a, b, use.names = FALSE) 0.031 0.032 0.049 0.034 0.036 1.474 100 c(c, d, use.names = FALSE) 0.031 0.031 0.035 0.034 0.035 0.064 100 c(a, d, use.names = FALSE) 0.031 0.031 0.049 0.034 0.035 1.452 100 c(a, b, use.names = TRUE) 0.031 0.031 0.055 0.034 0.036 2.094 100 c(a, d, use.names = TRUE) 0.510 0.526 0.588 0.549 0.617 1.998 100 c(c, d, use.names = TRUE) 0.780 0.815 0.886 0.841 0.944 1.430 100> profmem::profmem(c(c, d, use.names=FALSE))Rprofmem memory profiling of: c(c, d, use.names = FALSE) Memory allocations: bytes calls 1 80040 <internal> total 80040> profmem::profmem(c(c, d, use.names=TRUE))Rprofmem memory profiling of: c(c, d, use.names = TRUE) Memory allocations: bytes calls 1 80040 <internal> 2 160040 <internal> total 240080 /Henrik On Fri, Sep 23, 2016 at 10:25 AM, William Dunlap via R-devel <r-devel at r-project.org> wrote:> In Splus c() and unlist() called the same C code, but with a different > 'sys_index' code (the last argument to .Internal) and c() did not consider > an argument named 'use.names' special. > >> c > function(..., recursive = F) > .Internal(c(..., recursive = recursive), "S_unlist", TRUE, 1) >> unlist > function(data, recursive = T, use.names = T) > .Internal(unlist(data, recursive = recursive, use.names = use.names), > "S_unlist", TRUE, 2) >> c(A=1,B=2,use.names=FALSE) > A B use.names > 1 2 0 > > The C code used sys_index==2 to mean 'the last argument is the 'use.names' > argument, if sys_index==1 only the recursive argument was considered > special. > > Sys.funs.c: > 405 S_unlist(vector *ent, vector *arglist, s_evaluator *S_evaluator) > 406 { > 407 int which = sys_index; boolean named, recursive, names; > ... > 419 args = arglist->value.tree; n = arglist->length; > ... > 424 names = which==2 ? logical_value(args[--n], ent, S_evaluator) > : (which == 1); > > Thus there is no historical reason for giving c() the use.names argument. > > > Bill Dunlap > TIBCO Software > wdunlap tibco.com > > On Fri, Sep 23, 2016 at 9:37 AM, Suharto Anggono Suharto Anggono via > R-devel <r-devel at r-project.org> wrote: > >> In S-PLUS 3.4 help on 'c' (http://www.uni-muenster.de/ >> ZIV.BennoSueselbeck/s-html/helpfiles/c.html), there is no 'use.names' >> argument. >> >> Because 'c' is a generic function, I don't think that changing formal >> arguments is good. >> >> In R devel r71344, 'use.names' is not an argument of functions 'c.Date', >> 'c.POSIXct' and 'c.difftime'. >> >> Could 'use.names' be documented to be accepted by the default method of >> 'c', but not listed as a formal argument of 'c'? Or, could the code that >> handles the argument name 'use.names' be removed? >> ---------------- >> >>>>> David Winsemius <dwinsemius at comcast.net> >> >>>>> on Tue, 20 Sep 2016 23:46:48 -0700 writes: >> >> >> On Sep 20, 2016, at 7:18 PM, Karl Millar via R-devel <r-devel at >> r-project.org> wrote: >> >> >> >> 'c' has an undocumented 'use.names' argument. I'm not sure if this >> is >> >> a documentation or implementation bug. >> >> > It came up on stackoverflow a couple of years ago: >> >> > http://stackoverflow.com/questions/24815572/why-does- >> function-c-accept-an-undocumented-argument/24815653#24815653 >> >> > At the time it appeared to me to be a documentation lag. >> >> Thank you, Karl and David, >> yes it is a documentation glitch ... and a bit more: Experts know that >> print()ing of primitive functions is, eehm, "special". >> >> I've committed a change to R-devel ... (with the intent to port >> to R-patched). >> >> Martin >> >> >> >> >>> c(a = 1) >> >> a >> >> 1 >> >>> c(a = 1, use.names = F) >> >> [1] 1 >> >> >> >> Karl >> >> ______________________________________________ >> R-devel at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel
I'd expect that a lot of the performance overhead could be eliminated by simply improving the underlying code. IMHO, we should ignore it in deciding the API that we want here. On Fri, Sep 23, 2016 at 10:54 AM, Henrik Bengtsson <henrik.bengtsson at gmail.com> wrote:> I'd vote for it to stay. It could of course suprise someone who'd > expect c(list(a=1), b=2, use.names = FALSE) to generate list(a=1, b=2, > use.names=FALSE). On the upside, is the performance gain from using > use.names=FALSE. Below benchmarks show that the combining of the > names attributes themselves takes ~20-25 times longer than the > combining of the integers themselves. Also, at no surprise, > use.names=FALSE avoids some memory allocations. > >> options(digits = 2) >> >> a <- b <- c <- d <- 1:1e4 >> names(c) <- c >> names(d) <- d >> >> stats <- microbenchmark::microbenchmark( > + c(a, b, use.names=FALSE), > + c(c, d, use.names=FALSE), > + c(a, d, use.names=FALSE), > + c(a, b, use.names=TRUE), > + c(a, d, use.names=TRUE), > + c(c, d, use.names=TRUE), > + unit = "ms" > + ) >> >> stats > Unit: milliseconds > expr min lq mean median uq max neval > c(a, b, use.names = FALSE) 0.031 0.032 0.049 0.034 0.036 1.474 100 > c(c, d, use.names = FALSE) 0.031 0.031 0.035 0.034 0.035 0.064 100 > c(a, d, use.names = FALSE) 0.031 0.031 0.049 0.034 0.035 1.452 100 > c(a, b, use.names = TRUE) 0.031 0.031 0.055 0.034 0.036 2.094 100 > c(a, d, use.names = TRUE) 0.510 0.526 0.588 0.549 0.617 1.998 100 > c(c, d, use.names = TRUE) 0.780 0.815 0.886 0.841 0.944 1.430 100 > >> profmem::profmem(c(c, d, use.names=FALSE)) > Rprofmem memory profiling of: > c(c, d, use.names = FALSE) > > Memory allocations: > bytes calls > 1 80040 <internal> > total 80040 > >> profmem::profmem(c(c, d, use.names=TRUE)) > Rprofmem memory profiling of: > c(c, d, use.names = TRUE) > > Memory allocations: > bytes calls > 1 80040 <internal> > 2 160040 <internal> > total 240080 > > /Henrik > > On Fri, Sep 23, 2016 at 10:25 AM, William Dunlap via R-devel > <r-devel at r-project.org> wrote: >> In Splus c() and unlist() called the same C code, but with a different >> 'sys_index' code (the last argument to .Internal) and c() did not consider >> an argument named 'use.names' special. >> >>> c >> function(..., recursive = F) >> .Internal(c(..., recursive = recursive), "S_unlist", TRUE, 1) >>> unlist >> function(data, recursive = T, use.names = T) >> .Internal(unlist(data, recursive = recursive, use.names = use.names), >> "S_unlist", TRUE, 2) >>> c(A=1,B=2,use.names=FALSE) >> A B use.names >> 1 2 0 >> >> The C code used sys_index==2 to mean 'the last argument is the 'use.names' >> argument, if sys_index==1 only the recursive argument was considered >> special. >> >> Sys.funs.c: >> 405 S_unlist(vector *ent, vector *arglist, s_evaluator *S_evaluator) >> 406 { >> 407 int which = sys_index; boolean named, recursive, names; >> ... >> 419 args = arglist->value.tree; n = arglist->length; >> ... >> 424 names = which==2 ? logical_value(args[--n], ent, S_evaluator) >> : (which == 1); >> >> Thus there is no historical reason for giving c() the use.names argument. >> >> >> Bill Dunlap >> TIBCO Software >> wdunlap tibco.com >> >> On Fri, Sep 23, 2016 at 9:37 AM, Suharto Anggono Suharto Anggono via >> R-devel <r-devel at r-project.org> wrote: >> >>> In S-PLUS 3.4 help on 'c' (http://www.uni-muenster.de/ >>> ZIV.BennoSueselbeck/s-html/helpfiles/c.html), there is no 'use.names' >>> argument. >>> >>> Because 'c' is a generic function, I don't think that changing formal >>> arguments is good. >>> >>> In R devel r71344, 'use.names' is not an argument of functions 'c.Date', >>> 'c.POSIXct' and 'c.difftime'. >>> >>> Could 'use.names' be documented to be accepted by the default method of >>> 'c', but not listed as a formal argument of 'c'? Or, could the code that >>> handles the argument name 'use.names' be removed? >>> ---------------- >>> >>>>> David Winsemius <dwinsemius at comcast.net> >>> >>>>> on Tue, 20 Sep 2016 23:46:48 -0700 writes: >>> >>> >> On Sep 20, 2016, at 7:18 PM, Karl Millar via R-devel <r-devel at >>> r-project.org> wrote: >>> >> >>> >> 'c' has an undocumented 'use.names' argument. I'm not sure if this >>> is >>> >> a documentation or implementation bug. >>> >>> > It came up on stackoverflow a couple of years ago: >>> >>> > http://stackoverflow.com/questions/24815572/why-does- >>> function-c-accept-an-undocumented-argument/24815653#24815653 >>> >>> > At the time it appeared to me to be a documentation lag. >>> >>> Thank you, Karl and David, >>> yes it is a documentation glitch ... and a bit more: Experts know that >>> print()ing of primitive functions is, eehm, "special". >>> >>> I've committed a change to R-devel ... (with the intent to port >>> to R-patched). >>> >>> Martin >>> >>> >> >>> >>> c(a = 1) >>> >> a >>> >> 1 >>> >>> c(a = 1, use.names = F) >>> >> [1] 1 >>> >> >>> >> Karl >>> >>> ______________________________________________ >>> R-devel at r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-devel >>> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-devel at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel
>>>>> Karl Millar via R-devel <r-devel at r-project.org> >>>>> on Fri, 23 Sep 2016 11:12:49 -0700 writes:> I'd expect that a lot of the performance overhead could be eliminated > by simply improving the underlying code. IMHO, we should ignore it in > deciding the API that we want here. I agree partially. Even if the underlying code can be made faster, the 'use.names = FALSE' version will still be faster than the default, notably in some "long" cases. More further down. > On Fri, Sep 23, 2016 at 10:54 AM, Henrik Bengtsson > <henrik.bengtsson at gmail.com> wrote: >> I'd vote for it to stay. It could of course suprise someone who'd >> expect c(list(a=1), b=2, use.names = FALSE) to generate list(a=1, b=2, >> use.names=FALSE). On the upside, is the performance gain from using >> use.names=FALSE. Below benchmarks show that the combining of the >> names attributes themselves takes ~20-25 times longer than the >> combining of the integers themselves. Also, at no surprise, >> use.names=FALSE avoids some memory allocations. >> >>> options(digits = 2) >>> >>> a <- b <- c <- d <- 1:1e4 >>> names(c) <- c >>> names(d) <- d >>> >>> stats <- microbenchmark::microbenchmark( >> + c(a, b, use.names=FALSE), >> + c(c, d, use.names=FALSE), >> + c(a, d, use.names=FALSE), >> + c(a, b, use.names=TRUE), >> + c(a, d, use.names=TRUE), >> + c(c, d, use.names=TRUE), >> + unit = "ms" >> + ) >>> >>> stats >> Unit: milliseconds >> expr min lq mean median uq max neval >> c(a, b, use.names = FALSE) 0.031 0.032 0.049 0.034 0.036 1.474 100 >> c(c, d, use.names = FALSE) 0.031 0.031 0.035 0.034 0.035 0.064 100 >> c(a, d, use.names = FALSE) 0.031 0.031 0.049 0.034 0.035 1.452 100 >> c(a, b, use.names = TRUE) 0.031 0.031 0.055 0.034 0.036 2.094 100 >> c(a, d, use.names = TRUE) 0.510 0.526 0.588 0.549 0.617 1.998 100 >> c(c, d, use.names = TRUE) 0.780 0.815 0.886 0.841 0.944 1.430 100 >> >>> profmem::profmem(c(c, d, use.names=FALSE)) >> Rprofmem memory profiling of: >> c(c, d, use.names = FALSE) >> >> Memory allocations: >> bytes calls >> 1 80040 <internal> >> total 80040 >> >>> profmem::profmem(c(c, d, use.names=TRUE)) >> Rprofmem memory profiling of: >> c(c, d, use.names = TRUE) >> >> Memory allocations: >> bytes calls >> 1 80040 <internal> >> 2 160040 <internal> >> total 240080 >> >> /Henrik >> >> On Fri, Sep 23, 2016 at 10:25 AM, William Dunlap via R-devel >> <r-devel at r-project.org> wrote: >>> In Splus c() and unlist() called the same C code, but with a different >>> 'sys_index' code (the last argument to .Internal) and c() did not consider >>> an argument named 'use.names' special. Thank you, Bill, very much, for making the historical context clear, and giving us the facts, there. OTOH, it is also true in R, that c() and unlist() share code .. quite a bit less though .. but more importantly, the very original C code of Ross Ihaka (and possibly Robert Gentleman) had explicitly considered both extra arguments 'recursive' and 'use.names', and not just the first. The fact that c() has always been a .Primitive function and that these have no formals() had contributed to what I think to be a documentation glitch early on, and when, quite a bit later, we've added a fake argument list for printing, the then current documentation was used. This was the reason for declaring it a documentation "hole" rather than something we do not want. (read on) >>>> c >>> function(..., recursive = F) >>> .Internal(c(..., recursive = recursive), "S_unlist", TRUE, 1) >>>> unlist >>> function(data, recursive = T, use.names = T) >>> .Internal(unlist(data, recursive = recursive, use.names = use.names), >>> "S_unlist", TRUE, 2) >>>> c(A=1,B=2,use.names=FALSE) >>> A B use.names >>> 1 2 0 >>> >>> The C code used sys_index==2 to mean 'the last argument is the 'use.names' >>> argument, if sys_index==1 only the recursive argument was considered >>> special. >>> >>> Sys.funs.c: >>> 405 S_unlist(vector *ent, vector *arglist, s_evaluator *S_evaluator) >>> 406 { >>> 407 int which = sys_index; boolean named, recursive, names; >>> ... >>> 419 args = arglist->value.tree; n = arglist->length; >>> ... >>> 424 names = which==2 ? logical_value(args[--n], ent, S_evaluator) >>> : (which == 1); >>> >>> Thus there is no historical reason for giving c() the use.names argument. >>> >>> >>> Bill Dunlap >>> TIBCO Software >>> wdunlap tibco.com >>> >>> On Fri, Sep 23, 2016 at 9:37 AM, Suharto Anggono Suharto Anggono via >>> R-devel <r-devel at r-project.org> wrote: >>> >>>> In S-PLUS 3.4 help on 'c' (http://www.uni-muenster.de/ >>>> ZIV.BennoSueselbeck/s-html/helpfiles/c.html), there is no 'use.names' >>>> argument. >>>> >>>> Because 'c' is a generic function, I don't think that changing formal >>>> arguments is good. >>>> >>>> In R devel r71344, 'use.names' is not an argument of functions 'c.Date', >>>> 'c.POSIXct' and 'c.difftime'. You are right, Suharto, that methods for c() currently have no such argument. But again because c() is primitive and has a '...' at the beginning, this does not explicitly hurt, currently, does it? >>>> Could 'use.names' be documented to be accepted by the default method of >>>> 'c', but not listed as a formal argument of 'c'? >>>> Or, could the code that handles the argument name >>>> 'use.names' be removed? In principle, of course both could happen, and if one of these two was preferable to the current state, I'd tend to the first one: Consider 'use.names [= FALSE]' just an argument of the default method for c(), so existing c() methods would not have a strong need for updating. Notably, as the S4 generic for c, via lines 48-49 of src/library/methods/R/BasicFunsList.R , "c" = structure(function(x, ..., recursive = FALSE) standardGeneric("c"), signature="x") has never had 'recursive' as part of the signature.. (and yes, that line 48 does need an update too !!!). Martin >>>> ---------------- >>>> >>>>> David Winsemius <dwinsemius at comcast.net> >>>> >>>>> on Tue, 20 Sep 2016 23:46:48 -0700 writes: >>>> >>>> >> On Sep 20, 2016, at 7:18 PM, Karl Millar via R-devel <r-devel at r-project.org> wrote: >>>> >> >>>> >> 'c' has an undocumented 'use.names' argument. I'm not sure if this >>>> is >>>> >> a documentation or implementation bug. >>>> >>>> > It came up on stackoverflow a couple of years ago: >>>> >>>> > http://stackoverflow.com/questions/24815572/why-does- >>>> function-c-accept-an-undocumented-argument/24815653#24815653 >>>> >>>> > At the time it appeared to me to be a documentation lag. >>>> >>>> Thank you, Karl and David, >>>> yes it is a documentation glitch ... and a bit more: Experts know that >>>> print()ing of primitive functions is, eehm, "special". >>>> >>>> I've committed a change to R-devel ... (with the intent to port >>>> to R-patched). >>>> >>>> Martin >>>> >>>> >> >>>> >>> c(a = 1) >>>> >> a >>>> >> 1 >>>> >>> c(a = 1, use.names = F) >>>> >> [1] 1 >>>> >> >>>> >> Karl >>>>