similar to: export C++ array to R

Hi everybody, I have been interfacing some C++ library code into an R package but ran into optimization issues specific to memory management that require some insight into the GC. One of the C++ libraries returns simple vectors of integers, doubles and complex which are allocated and managed from the library itself. I cannot know the length of the array beforehand, so I cannot pre-allocate that

Hi , For our production package i need to create a dataframein C . So I wrote the following code SEXP dfm ,head,df , dfint , dfStr,lsnm; *SEXP valueVector[2];* char *ab[3] = {"aa","vv","gy"}; int sn[3] ={99,89,12}; char *listnames[2] = {"int","string"}; int i,j; //============================= PROTECT(df = allocVector(VECSXP,2));

>From copyVector in duplicate.c : void copyVector(SEXP s, SEXP t) { int i, ns, nt; nt = LENGTH(t); ns = LENGTH(s); switch (TYPEOF(s)) { ... case INTSXP: for (i = 0; i < ns; i++) INTEGER(s)[i] = INTEGER(t)[i % nt]; break; ... could that be replaced with : case INTSXP: for (i=0; i<ns/nt; i++) memcpy((char *)DATAPTR(s)+i*nt*sizeof(int),

Experimenting with altrep objects and v3 serialization, I discovered a possible bug. Calling DATAPTR on a compact_intseq object returns a pointer to the expanded integer sequence in memory. If you modify this data, the object values appear to be changed. However, if the compact_intseq object is then serialized (with version=3), only the original integer sequence info is written. For example,

Hi, I have been studying the R manual on lists but cannot seem to create a simple R list in C - I keep on getting "'dimnames' applied to non-array" whenever I attempt to assign names to the list elements: Wanted output a list structure something like [ type="Bid", price=2.0, volume=1000 ] I can get up to a list of [ "Bid2, 2.0, 1000 ] But for the life of

Hi Gabriel, Thanks for your explanation, I totally understand that it is almost impossible to change the data structure of STRSXP. However, what I'm proposing is not about changing the internal representation, but rather about how we design and use the ALTREP API. I might do not state the workarounds clearly as English is not my first language. Please let me explain them again in detail.

Sorry to ask about a bit drifted topic, but will there be an alternative API to DATAPTR? > DATAPTR is not in the API and can't be at least in this form I believe it's vital for ALTREP to return the pointer to the expanded version of a SEXP just like the implementation in base R does [1]. At least, VECSXP has no other measure to expose the pointer if I understand correctly. Best,

there is my code,  expect return value  is a data frame but R say it is list: SEXP Julia_R_MD_NA_DataFrame(jl_value_t* Var) {  SEXP ans,names,rownames;  char evalcmd[4096];  int i;  const char* dfname="DataFrameName0tmp";  jl_set_global(jl_main_module, jl_symbol(dfname), (jl_value_t*)Var);  //Get Frame cols   sprintf(evalcmd,"size(%s,2)",dfname);  jl_value_t*

Hi, I am looking for C/C++ codes for computing generalized inverse of a matrix. Can anyone help me in this regard? Thanks, Mahbub.

On Sat, 8 Jun 2024, Ben Bolker wrote: > The ASAN errors occur *even if the zero-length object is not actually > accessed*/is used in a perfectly correct manner, i.e. it's perfectly legal in > base R to define `m <- numeric(0)` or `m <- matrix(nrow = 0, ncol = 0)`, > whereas doing the equivalent in Rcpp will (now) lead to an ASAN error. > > i.e., these are *not*

Hello from Bioconductor, I'm developing a package to share R objects across clusters using boost library. The concept is similar to mmap package: https://cran.r-project.org/web/packages/mmap/index.html . However, I have a problem when I was trying to write Dataptr_method for the alternative string. Based on my understanding, the return value of the Dataptr_method function should be a vector

Hi , I am trying to create a dataframe in C and sebd it back to R. Can anyone point me to the part of the source code where it is doing , let me explain the problem I am having . -------------------------------------------------------------------- My simple implementation is like this SEXP formDF() { SEXP dfm ,df , dfint , dfStr,lsnm; char *ab[3] =

Hi all I recently started to write a matrix exponentiation operator for R (by adding a new operator definition to names.c, and adding the following code to arrays.c). It is not finished yet, but I would like to solicit some comments, as there are a few areas of R's internals that I am still feeling my way around. Firstly: 1) Would there be interest in adding a new operator %^% that performs

Hi I'm trying to develop some C code to find the fixpoint of a contraction mapping, the code compiles and gives the right results when executed in R. However R-gui session is frequently terminated. I'm suspecting some access violation error due to the exception code 0xc0000005 In the error report windows 10 gives me. It is the first time I'm writing any C-code so I'm guessing I

Dear R-dev, I would like to accelerate my R computation by using parallel OpenMP compilers (e.g from Pathscale) on a 2-processor AMD server and I would like to know whether R is a tread safe library. The main kernel of the OpenMP parallelization is a C SEXP function that performs the computational routine in parallel with: ******************* SEXP example(SEXP list, SEXP expr, SEXP rho) {

Hi, I'm troubleshooting some native code on Windows that very occationally (and semi-randomly) crashes R. Already looked at "everything", I just want to double check that it is safe to UNPROTECT() allocated variables as soon as they are assigned to, say, a PROTECTed list. >From (R v2.3.0) Section 5.7.1 "Handling the effects of garbage collection" in "Writing R

Dear list, I am trying to implement a publish-subscribe mechanism in for an embedded R interpreter. But somehow my registered closures seem to get collected by the GC, even though I have protected them. I have reducted my code to the following sample. Sorry if it is a little verbose. The first couple of call of calls still work, but at some point one of the callbacks (callback1 in my

dear people, i need to code a function in C working in R and receives two R SEXP objects as parameters, where one is a list and another is a vector of integers: void f(SEXP list, SEXP vector) { ... return list; } and it should return the given list with the integer vector concatenated at the end (as the last element of the list). the list can be really big so i would not like to create a

Dear R developers, I've just encountered one "feature" of R-C extensions. If it is known, I would be thankful for any hints why it works this way (I found the way around, which is also mentioned here, but maybe it is not the best one). If it is however unknown, it might be considered for a "wish list". Consider a simple "aka" C function (the original

I believe there is a memory leak in isoreg in the current version of R, as I believe the following shows > gc() used (Mb) gc trigger (Mb) max used (Mb) Ncells 120405 3.3 350000 9.4 350000 9.4 Vcells 78639 0.6 786432 6.0 392463 3.0 > for(k in 1:100) { + + y <- runif(10000) + isoreg(x,y) + } > rm(x) > rm(y) > gc() used (Mb) gc