similar to: evaluating R expressions from C

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 experts! I want to evaluate expressions from within C code. For instance, I want this code: /* ============ -- C code -- ============== */ #include <R.h> #include <Rinternals.h> SEXP foo(SEXP expr, SEXP rho) { SEXP x; PROTECT(x = allocVector(REALSXP, 1)); REAL(x)[0] = 1; UNPROTECT(1); return

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, 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:

Dear all, [system and version information below] I am trying to modify a C function for finding the root of an expression. The function is to be called from R as .Call with input parameters: f: expression for which we will find the root guesses: interval for the solution stol: tolerance rho: environment The original functions I use are: SEXP mkans(double x) { SEXP ans; PROTECT(ans =

Dear all, [system and version information below] I am trying to modify a C function for finding the root of an expression. The function is to be called from R as .Call with input parameters: f: expression for which we will find the root guesses: interval for the solution stol: tolerance rho: environment The original functions I use are: SEXP mkans(double x) { SEXP ans; PROTECT(ans =

I was trying to find source for optimize and I ran across function (f, interval, ..., lower = min(interval), upper = max(interval), maximum = FALSE, tol = .Machine$double.eps^0.25) { if (maximum) { val <- .Internal(fmin(function(arg) -f(arg, ...), lower, upper, tol)) list(maximum = val, objective = f(val, ...)) } else { val <-

Hi, I'm wondering if this code from the "Writing R Extensions" manual is really safe: SEXP mkans(double x) { SEXP ans; PROTECT(ans = allocVector(REALSXP, 1)); REAL(ans)[0] = x; UNPROTECT(1); return ans; } double feval(double x, SEXP f, SEXP rho) { defineVar(install("x"), mkans(x), rho);

Hi everyone, I am starting learn to call C code from within R. So far, I've been trying toy problems to see if I can get them to work. One of the things I'd like to do is pass an arbitrary R function to C, evaluate the value in the C code using eval, and then return it. I also want to allow an arbitrary number of arguments to the function using "...". The code for my toy

Hi, OK, if you try to explicitly make them generic, you are told that they are implicitly already generic: > setGeneric("is.finite", function(from, ...) standardGeneric("is.finite")) Error in setGeneric("is.finite", function(from, ...) standardGeneric("is.finite")) : "is.finite" is a primitive function; methods can be defined, but the

Hello all, I don't know if it is possible, but I would like to use do.call in C code in my package. The function do.call is defined as > do.call function (what, args, quote = FALSE, envir = parent.frame()) { if (!is.list(args)) stop("second argument must be a list") if (quote) { enquote <- function(x) as.call(list(as.name("quote"),

Hi, I am learning R by reading R source code. Here is one question I have about the optim function in R. The context : In the optim.R, after all the prep steps, the main function call call is made via : .External2(C_optim, par, fn1, gr1, method, con, lower, upper). So, it seems to me, to follow what is going on from here, that I should read the optim function in \src\library\stats\src\optim.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) {

Hi All, I have a few small questions about the usage of the C findVar( ) function when used in C code called with '.Call'. In my case I create an R function with an argument. This function calls some C code in which I use findVar( ) to retrieve the values from the argument. Ofcourse normally I would just give the values as argument to .Call, but in my project I need to use findVar for

Hi, I'm writing a C function that has to call a R function with multiple arguments. I've read the relevant section in Writing R Extensions, and searched the R site, mailing lists as well as rseek. I managed to call the function, but I'm now having trouble creating the argument list. I tried to create a pairlist of the arguments and send it to the R function. The R function however

Hi, I'm quite knew in R, so I might not have the R specific jargon. But here is my problem, I'm trying to access and use variabels given by a function environment, more specifically the rho in do_optim in src/main/optim.c According to the documentation http://cran.r-project.org/doc/manuals/R-ints.html#The-_0027data_0027 the envsxp is defined as a tagged pairlist. "ENVSXP: Pointers

The Bioconductor build for a package DirichletMultinomial on R Under development (unstable) (2013-02-26 r62077) -- "Unsuffered Consequences" at http://bioconductor.org/checkResults/devel/bioc-LATEST/DirichletMultinomial/george2-buildsrc.html shows * creating vignettes ... ERROR ... Error: processing vignette ?DirichletMultinomial.Rnw? failed with diagnostics: chunk 21 (label

Hi All! I'm a new subscriber to this mailing list. I'm writing an R extension with C linked code having a minimization function letting me pass it an objective function with a GENERIC number of arguments and letting me to optimize over a specific one among them if there are many. ################################################# ############### IPOTETICAL MAIN ###############

Does anyone have an example of calling primitive or internal functions from C code that they would share with me? I am having trouble trying to figure out how to construct the proper arguments to pass to "do_subset_dflt" Here is the prototype: SEXP do_subset_dflt(SEXP call, SEXP op, SEXP args, SEXP rho); The R_FunTab from "names.c" gives some additional information on the

Does anyone have an example of calling primitive or internal functions from C code that they would share with me? I am having trouble trying to figure out how to construct the proper arguments to pass to "do_subset_dflt" Here is the prototype: SEXP do_subset_dflt(SEXP call, SEXP op, SEXP args, SEXP rho); The R_FunTab from "names.c" gives some additional information on the