similar to: Strange Behavior in RNG

Hello, I?m experimenting with ALTREP and was wondering if there is a preferred way to create an ALTREP wrapper vector without using .Internal(wrap_meta(?)), which R CMD check doesn?t like since it uses an .Internal() function. I was trying to create a factor that used an ALTREP integer, but attempting to set the class and levels attributes always ended up duplicating and materializing the

Hello, I have encountered two bugs when using ALTREP APIs. 1. STDVEC_DATAPTR >From RInternal.h file it has a comment: /* ALTREP support */ > void *(STDVEC_DATAPTR)(SEXP x); However, this comment might not be true, the easiest way to verify it is to define a C++ function: void C_testFunc(SEXP a) > { > STDVEC_DATAPTR(a); > } and call it in R via > a=1:10 > >

Hello Luke and Gabriel, Thank you very much for your quick responses. The explanation of STDVEC is very helpful and I appreciate it! For the wrapper, I have a few new questions. 1. Like Luke said a mutable object is not possible. However, I noticed that there is one extra argument *deep* in the function duplicate. I've googled all the available documentation for ALTREP but I did not find

I ran into strange behavior when removing names. Two ways of removing names: i <- rep(1:4, length.out=20000) k <- c(a=1, b=2, c=3, d=4) x1 <- unname(k[i]) x2 <- k[i] x2 <- unname(x2) Are they identical? identical(x1,x2) # TRUE but no identical(serialize(x1,NULL),serialize(x2,NULL)) # FALSE But problem is with serialization type 3, cause:

Hi Jiefei and Kylie, Great to see people engaging with the ALTREP framework and identifying places we may need more tooling. Comments inline. On Thu, Jul 18, 2019 at 12:22 PM King Jiefei <szwjf08 at gmail.com> wrote: > > If that is the case and you are 100% sure the reference number should be 1 > for your variable *y*, my solution is to call *SET_NAMED *in C++ to reset > the

I've been playing with passing arguments to .C(), and found that replacing as.double(x) with if(is.double(x)) x else as.double(x) saves time and avoids one copy, in the case that x is already double. I suggest modifying as.double to avoid the extra copy and just return x, when x is already double. Similarly for as.integer, etc. [[alternative HTML version deleted]]

My understanding is that R will not make copies of lists if there is only one reference to the object. However, I've encountered a case where R does make copies, even though (I think) there should be only one reference to the object. I hope that someone could shed some light on why this is happening. I'll start with a simple example. Below, x is a list with one element, and changing that

Hi all, The coercion function defined for the ALTREP object will not be called by R when an assignment operation implicitly introduces coercion for a large ALTREP object. For example, If I create a vector of length 10, the ALTREP coercion function seems to work fine. ``` > x <- 1:10 > y <- wrap_altrep(x) > .Internal(inspect(y)) @0x000000001f9271c0 13 INTSXP g0c0 [REF(2)] I am

Hi Kylie, For your question, I don't think a wrapper can completely solve your problem. The duplication occurs since your variable y has more than 1 reference number( Please see highlighted), so even you have a wrapper, any changes on the value of the wrapper still can trigger the duplication. > .Internal(inspect(y)) > @7fb0ce78c0f0 13 INTSXP g0c0 *[NAM(7)]* matter vector (mode=3,

Hello, I've created this class: setClass("example", representation ( size = "numeric", id = "character" ) ) Suppose I create a new instance of this class: > x <- new("example", 4, "id_value") This creates an S4 object with two slots. Am I correct in thinking that slots are "filled" by SEXPs?

Dear Yihui, Thanks a lot for your help! Unfortunately, I was not able to reproduce this. I've tried creating files with Chinese characters in their names and populating them with valid UTF-8 and valid non-UTF-8 text, but R seems to be able to list them all in my case. I'm running a US English evaluation ISO image of a slightly newer build of Windows 10, and I also compiled R-4.3.1 from

Hi devel team, I'm working on C/C++ level ALTREP compatibility for a package. The package previously used pointers to access the data of a SEXP, so it would not work for some ALTREP objects which do not have a pointer. I plan to rewrite the code and use functions like get_elt, get_region, and get_subset to access the values of a vector, so I have a few questions for ALTREP: 1. Since an

Hi Gabriel, here is a simple package for reproducing the problem. https://github.com/Jiefei-Wang/testPkg Best, Jiefei On Thu, Oct 8, 2020 at 5:04 AM Gabriel Becker <gabembecker at gmail.com> wrote: > Jiefei, > > Where does the code for your altrep class live? > > Thanks, > ~G > > On Wed, Oct 7, 2020 at 4:25 AM Jiefei Wang <szwjf08 at gmail.com> wrote: >

Hi, I just found a strange increase in the reference number and I'm wondering if there is any reason for it, here is the code. > a=c(1,2,3) > .Internal(inspect(a)) @0x000000001bf0b9b0 14 REALSXP g0c3 [NAM(1)] (len=3, tl=0) 1,2,3 > is.vector(a) [1] TRUE > .Internal(inspect(a)) @0x000000001bf0b9b0 14 REALSXP g0c3 [NAM(7)] (len=3, tl=0) 1,2,3 The variable *a* initially has one

Sorry for post a lot of things, for the first part of code, I copied my C++ iter macro by mistake(and you can see an explicit type casting). Here is the macro definition from R_exts/Itermacros.h #define ITERATE_BY_REGION_PARTIAL(sx, px, idx, nb, etype, vtype, \ strt, nfull, expr) do { \ * const** etype *px = DATAPTR_OR_NULL(sx); *

A copy of this question can be found on Cross Validated: https://stats.stackexchange.com/questions/645362 I am estimating a system of seemingly unrelated regressions (SUR) in R. Each of the equations has one unique regressor and one common regressor. I am using `gmm::sysGmm` and am experimenting with different weighting matrices. I get the same results (point estimates, standard errors and

Hi Jiefei and Duncan, I suspect what is likely happening is that one of ENSURE_NAMEDMAX or MARK_NOT_MUTABLE are being hit for x. These used to set named to 3, but now set it to 7 (ie the previous and current NAMEDMAX value, respectively). Because these are macros rather than C functions, its not easy to figure out why one of them is being invoked from do_isvector (a cursory exploration

Generally speaking, this sort of detailed statistical question about a speccial package in R does not get a reply on this general R programming help list. Instead, I suggest you either email the maintainer (found by ?maintainer) or ask a question on a relevant R task view, such as https://cran.r-project.org/web/views/Econometrics.html . (or any other that you judge to be more appropriate).

I'm interested in the difference between these two intuitively equivalent sequences that produce different results (in R version 2.13.1 (2011-07-08) 32-bit). I think R's reference counting optimization is causing this difference in behavior. > a <- 1 > a+{a[1] <- 20} [1] 21 > a <- 1 > a[1] <- 1 > a+{a[1] <- 20} [1] 40 Is one of these the "correct"

Hi Bob, Thanks for sending around the link to that. It looks mostly right and looks like a useful onramp. There are a few things to watch out for though (I've cc'ed Romain so he's aware of these comments). @romain I hope you taake the following comments as they are intended, as help rather than attacks. The largest issue I see is that the contract for Get_region is that it *populates