similar to: Get the tail of a list in C

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) {

Dear R-devel, A couple of weeks ago I started to use the R C API for package development. Without knowing much about C, I've been able to write some routines sucessfully... until now. My problem consists in dynamically creating a list ("L1") of lists using .Call, the tricky part is that each element of the "mother list" contains two vectors (INTSXP and REALEXP types) with

I am currently puzzled by a passage in the R Extensions manual, section 5.10: SEXP lapply(SEXP list, SEXP expr, SEXP rho) { R_len_t i, n = length(list); SEXP ans; if(!isNewList(list)) error("`list' must be a list"); if(!isEnvironment(rho)) error("`rho' should be an environment"); PROTECT(ans = allocVector(VECSXP, n));

Dear R .Call() insiders, Can someone enlighten me how to properly finalize external pointers in C code (R-2.5.1 win)? What is the relation between R_ClearExternalPtr and the finalizer set in R_RegisterCFinalizer? I succeeded registering a finalizer that works when an R object containing an external pointer is garbage collected. However, I have some difficulties figuring out how to do that in an

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

Hello, I create a VECSXP(call it A) with size N(~ 5000), i then proceed to fill the elements and find out I don't need to fill more than M (M<< N). Thus if i return A to the user's R code, he/she will see a list of length 5K of which N-M are NULLs. To avoid this, I create a new VECSXP B of length M and /duplicate/ the elements of A. Since I do this often, it appears to be wasteful,

Hello, I have created a vector with 2 elements(see code below) I am calling this function many thousands of times (hundreds of thousands) after some time i get *** caught segfault *** address 0x5, cause 'memory not mapped' However, if i dont set the R_NamesSymbol, I do not get any such error. Am I doing this correctly? Thank you Saptarshi ==CODE=== // kxp and usar are two SEXP's

I've looked at how to speed up the transpose function in R (ie, t(X)). The existing code does the work with loops like the following: for (i = 0; i < len; i++) REAL(r)[i] = REAL(a)[(i / ncol) + (i % ncol) * nrow]; It seems a bit optimistic to expect a compiler to produce good code from this. I've re-written these loops as follows: for (i = 0, j = 0; i<len; i +=

Thank you to everyone who responded to my previous post regarding the integration into R of C programs that use external libraries. I have another issue that I simply have not been able to figure out using documentation, list archives, and so forth. I have data that is stored in R lists. I would like to pass the list to C code using the .Call function, perform mathematical operations on the

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

Assume a C program invoked by .Call, that returns a list. Near the top of the program we allocate space for all the list elements. (It is my habit to use "xyz2" for the name of the R object and "xyz" for the pointer to its contents.) PROTECT(means2 = allocVector(REALSXP, nvar)); means = REAL(means2); PROTECT(u2 = allocVector(REALSXP, nvar)); u =

Hi, I'd like to construct an R list object in C++, fill it with relevant data, and pass it to an R function which will return a different list object back. I have browsed through all the R manuals, and examples under tests/Embedding, but can't figure out the correct way. Below is my code snippet: #include <Rinternals.h> // Rf_initEmbeddedR and other setups already performed

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*

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

Hello: I was hoping to get some advice about how to return a tree (basically a linked list -- with each node containing a parent, left, and right node pointers) from a C routine back into R. Each node itself contains several attributes (a double, a char *, an int, and a void * ) Initially I was thinking I could just return to R a SEXP containing a pointer to the Root Node, but then realized

Hi there I'm loking for a time-measurement to measure time-differences in milliseconds. On my search, I only found the following: - package "base": Sys.time() -> only second-accuracy - package "R.utils": System$currentTimeMillis() -> returns integer of milliseconds, but accuracy is only whole seconds too. At the moment I run every bit of code to measure

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

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] =

I'm trying to generate an R interface for a library that's commonly used and I'm currently writing wrapper functions for file i/o and return an object (list?) that contains the elements of the C structure. For example, reading a file that contains: struct CONFIG_RECORD { char coeffs_filename[256]; char species_filename[256]; unsigned long

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