similar to: returning an empty list.

Hello All, I recently upgraded from R-1.1.1 to R-1.2.2. I have an R function that uses .Call() to return a list from C code. The C code has the form: SEXP function(SEXP var) { SEXP rlist ; PROTECT(rlist = NEW_LIST(3)) ; VECTOR_PTR(rlist)[0] = NEW_INTEGER(1) ; VECTOR_PTR(rlist)[1] = NEW_STRING(1) ; ... UNPROTECT(1) ; return(rlist) ; } When I try to

I have a few simple questions about the usage of PROTECT, more specifically how careful one needs to be. Simple yes/no answers are fine. Most of the uses I have seen do protection when memory is allocated. But what if one just want to assign a value of another function to a variable. Say eg. that foo is a function that returns a SEXP. Would the following code be fine? SEXP bar;

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 try to create a big treelike list structure using the RDefines/RInternal macros. The tree carries information at each node (attribute list) and at each leaf (vector). My understanding is that for each node I add to the binary tree I have to call PROTECT(newnode = NEW_LIST(2)); and cannot UNPROTECT before I return the whole tree. Same story for node attributes and leaf vectors. However, this

Hello, I call a function via .Call passing to it a raw vector(D) and an integer(I) The vector is a series K1,KData1, V1,VData1, K2, KData2, ... where the integer K1 is the length of Data1 and similarly for Ki (wrt Datai)(similarly for V*) There 2*I such pairs( (Ki,KDatai), (Vi,VDatai)) The numbers Ki(and Vi) are written in network order. I am returning a list of I elements each element a

Hello, I'm evaluating this expression expression({ for(x in 1:5){ .Call('rh_status','x') }}) a million times from a program with R embedded in it. I have attached reproducible code that crashes with Program received signal SIGSEGV, Segmentation fault. 0x00002b499ca40a6e in R_gc_internal (size_needed=0) at memory.c:1309 1309 FORWARD_NODE(R_PPStack[i]); Current language:

I've been inspired to look at the R source code by some strange timing results that I wrote about on my blog at radfordneal.wordpress.com (see the posts on "Speeding up parentheses..." and "Two surprising things...". I discovered that the strange speed advantage of curly brackets over parentheses is partially explained by an inefficiency in the evalList and

Hello Group, I could use an advice on how SEXP handles work. My aim is to implement a system where I initially set a few global variables that are used for communication between C and R code. Then I do some work with R code and periodically call a function of my own that will update the system state. Such a design is useful for many purposes (for GUIs to name one). I am not entirely sure that R

Hi All, I was reading the R extension manual section 5.11 ( Evaluating R expression from C) and I tried to build a simple call to the sum function. Please see below. call_to_sum <- inline::cfunction( language = "C", sig = c(x = "SEXP"), body = " SEXP e = PROTECT(lang2(install(\"sum\"), x)); SEXP ans = PROTECT(eval(e, R_GlobalEnv)); UNPROTECT(2); return

Dear R Gurus, I would very much appreciate some help with this code snippit from my RODBC package. R crashes or exhibits bizarre behaviour when repeatedly fetching large numbers of rows. Examples: > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx 3rd

On 6/30/20 1:06 PM, Jan Gorecki wrote: > It is quite known that R documentation on R C api could be improved... Please see "5.11 Evaluating R expressions from C" from "Writing R Extensions" Best Tomas > Still R-package-devel mailing list should be preferred for this kind > of questions. > Not sure if that is the best way, but works. > > call_to_sum <-

I want to write an R function using R's C interface that takes a 2-column matrix of increasing, non-overlapping integer intervals and returns a list with those intervals plus some added intervals, such that there are no gaps. For example, it should take the matrix rbind(c(5L, 6L), c(7L, 10L), c(20L, 30L)) and return list(c(5L, 6L), c(7L, 10L), c(11L, 19L), c(20L, 30L)). Because the output is

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 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

WRE explains that R_alloc() can be used to allocate memory which automatically gets released by R at the end of a .C, .Call or .External, even in the case of an error or interruption. This is a really great feature to prevent memory leaks. I was wondering if there is a way to extend this mechanism to allow for automatically running UNPROTECT and custom finalizers at the end of a .Call as well.

Consider the C (or C++) code called from the .Call interface: SEXP foo() { SEXP *p = PROTECT(allocVector(REALSXP, 10)); ... UNPROTECT(1); return p; } Why is there no danger that the allocated memory will be garbage collected after the UNPROTECT, but before the return of p? I have used code like this for some time and have never had a problem, but I'm not sure if/why it is guaranteed

When large calls cause errors R may stall for extended periods.? This is particularly likely to happen with `do.call`, as in this example with a 24 second stall: ??? x <- runif(1e7) ??? system.time(do.call(paste0, list(abs, x)))? # intentional error ??? ## Error in (function (..., collapse = NULL)? : ??? ##?? cannot coerce type 'builtin' to vector of type 'character' ??? ##

Hello, I submit a patch for review that implements code coverage tracing in the R interpreter. It records the lines that are actually executed and their associated frequency for which srcref information is available. I perfectly understands that this patch will not make its way inside R as it is, that they are many concerns of stability, compatibility, maintenance and so on. I would like to have

I am trying to use a custom S4 object in my C code and I cannot get the access to its slots working. The following is a toy example, but even this crashes. In R I have: setClass("pd", representation(data="numeric")) x <- new("pd", data=1:5) test <- function(pd.obj) { res <- .C("TestFun", pd.obj) res} test(x) (Of couse

Hi all, I am using R-3.0.1 under Linux platform to embed R into my C++ code. I am facing an error while executing more than 1 R-expressions parallelly. I am executing round(X) and abs(X) parallelly on a set of 50 input rows which resulted in segmentation fault after getting the following errors. Error: unprotect_ptr: pointer not found Error: argument to 'findVar' is not an environment