similar to: Confused about NAMED

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

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

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 think there is an inconsistency in the handling of the compact form of the row.names attributes. When n is the number of rows of a data.frame, the compact form is c(NA_integer_,-n), as in: > d <- data.frame(x=1:10) > .Internal(inspect(d)) @104f174a8 19 VECSXP g0c1 [OBJ,NAM(2),ATT] (len=1, tl=0) @103a7dc60 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,... ATTRIB: @104959380

Hi Lille, Is it possible you're looking for tracemem() or inspect() ? > x <- data.frame(z = 1:10)> tracemem(x)[1] "<0x55aa743e0bc0>" > x[1] <- 2Ltracemem[0x55aa743e0bc0 -> 0x55aa778f6ad0]: tracemem[0x55aa778f6ad0 -> 0x55aa778f6868]: [<-.data.frame [<- tracemem[0x55aa778f6868 -> 0x55aa778f5b48]: [<-.data.frame [<- >

Specifically, the srcfile attribute of the srcref attribute of the two instances of the functions contain different environments, AFAICT. Environments are compared only by exact pointer, so this forces return FALSE. Snippets from .Internal(inspect(x)) and .Internal(inspect(y)): @cca008 03 CLOSXP g0c0 [MARK,NAM(2),ATT] FORMALS: @604b58 00 NILSXP g0c0 [MARK,NAM(2)] BODY: @cc9650 06 LANGSXP

Hello, Since people have whisperred about Rcpp, I'd like to play too. > On 11/15/2010 07:45 AM, Patrick Leyshock wrote: >> Very helpful, thank you. >> >> A couple other questions, please: >> >> 1. I've got a function written in C, named "my_c_function". In my R >> code I call this function, passing to it an INTSXP and a STRSXP, >>

On Fri, 5 Aug 2016, Winston Chang wrote: > 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

Very interesting: > .Internal(inspect(k[i])) @10a4bc000 14 REALSXP g0c7 [ATT] (len=20000, tl=0) 1,2,3,4,1,... ATTRIB: @7fa24f07fa58 02 LISTSXP g0c0 [REF(1)] TAG: @7fa24b803e90 01 SYMSXP g0c0 [MARK,REF(5814),LCK,gp=0x6000] "names" (has value) @10a4e4000 16 STRSXP g0c7 [REF(1)] (len=20000, tl=0) @7fa24ba575c8 09 CHARSXP g0c1 [MARK,REF(35005),gp=0x61] [ASCII] [cached]

Hello, I would like for my C function to be able to manipulate some values stored in an R data frame. To achieve this, a need the (real) memory address where the R data frame stores its data (hopefully in a contiguous way). Then, from R, I call the C function and passing this memory address as a parameter. The question: how can we get the memory address of the R data frame? Thank you! L.

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?

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

I'm confused by this: > identical(function() {}, function() {}) [1] FALSE Yet, after loading the Matrix package (which redefines det), the following is checked (in library.checkConflicts): > identical(get("det", baseenv()), get("det", asNamespace("Matrix")), ignore.environment=T) [1] TRUE I've looked at the code in identical.c and for closures it

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:

Reading "R Internals" made me believe that R_UnboundValue was a placeholder that would be skipped over in variable lookup. viz. the section of R Internals "Hash tables" says "items are not actually deleted but have their value set to R_UnboundValue.", which seems to align with what I read in envir.c. So, I reasoned, if I have a function that returns R_UnboundValue,

Hi I'm trying to implement something similar to the following R snippet using C. I seem to have hit the wall on accessing class slots using C. library(fPortfolio) lppData <- 100 * LPP2005.RET[, 1:6] ewSpec <- portfolioSpec() nAssets <- ncol(lppData) setWeights(ewSpec) <- rep(1/nAssets, times = nAssets) ewPortfolio <- feasiblePortfolio( data = lppData, spec = ewSpec,

Hello All, I tried the sample code from the help. Although '{' is assigned to 'do', the call syntaxes for 'do' and '{' are not the same ('do' has ','s, but '{' has line breaks). I guess there is a difference in parsing the code block of 'do' and the code block of '{'. Could you please let me know some internal details so that

> .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

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]]

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,...