[Rd] Result of 'seq' doesn't use compact internal representation

[Luke Tierney]

Thanks -- I'll commit a fix after some testing.

Best,

luke

On 04/29/2018 06:22 AM, Duncan Murdoch wrote:
> On 28/04/2018 11:11 PM, Suharto Anggono Suharto Anggono via R-devel wrote:
>>> .Internal(inspect(1:10))
>> @300e4e8 13 INTSXP g0c0 [NAM(3)]  1 : 10 (compact)
>>> .Internal(inspect(seq(1,10)))
>> @3b6e1f8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,...
>>> system.time(1:1e7)
>>     user  system elapsed
>>        0       0       0
>>> system.time(seq(1,1e7))
>>     user  system elapsed
>>     0.05    0.00    0.04
>>
>> It seems that result of function 'seq' doesn't use compact internal 
>> representation. However, looking at the code of function 
>> 'seq.default', seq(1,n) produces 1:n. What is going on?
> 
> It looks like it is related to using compiled or interpreted code:
> 
>  > library(gtools)
>  > seq2 <- unByteCode(seq.default)
>  > .Internal(inspect(seq.default(1,10)))
> @7fa53847dcd8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,...
>  > .Internal(inspect(seq2(1,10)))
> @7fa537fa0bf0 13 INTSXP g0c0 [NAM(3)]  1 : 10 (compact)
> 
> Duncan Murdoch
> 
>>
>>> h <- seq.default
>>> environment(h) <- .GlobalEnv
>>> library(compiler)
>>> enableJIT(0)
>> [1] 3
>>> .Internal(inspect(h(1,10)))
>> @375ade8 13 INTSXP g0c0 [NAM(3)]  1 : 10 (compact)
>>
>> A non-byte-compiled version of function 'seq.default' can produce 
>> object that uses compact internal representation.
>>
>>
>>> sessionInfo()
>> R version 3.5.0 (2018-04-23)
>> Platform: i386-w64-mingw32/i386 (32-bit)
>> Running under: Windows XP (build 2600) Service Pack 3
>>
>> Matrix products: default
>>
>> locale:
>> [1] LC_COLLATE=English_United States.1252
>> [2] LC_CTYPE=English_United States.1252
>> [3] LC_MONETARY=English_United States.1252
>> [4] LC_NUMERIC=C
>> [5] LC_TIME=English_United States.1252
>>
>> attached base packages:
>> [1] compiler  stats     graphics  grDevices utils     datasets  methods
>> [8] base
>>
>> ______________________________________________
>> 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

-- 
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:   luke-tierney at uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu