similar to: Evaluating expressions from within C code

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);

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 am occasional getting "Segmentation Fault - core dumped" in R 0.62.3 (I think more often then I did in 0.62.2). I have not been able to do this in any reliably reproducible way yet, but thought I would mention the problem in case some else can isolate it. Paul Gilbert -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read

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-help, how could I create an R call in C code using lang2 with 2 and more arguments? I tried this code: SEXP f(SEXP fn, SEXP rho) { SEXP R_fcall, x, y; PROTECT(R_fcall = lang2(fn, R_NilValue)); PROTECT(x = allocVector(REALSXP, 1)); PROTECT(y = allocVector(REALSXP, 1)); REAL(x)[0] = 10; REAL(y)[0] = 20; SETCADR(R_fcall, x); SETCADR(R_fcall, y);

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

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 experts. 'D()' function recognizes some of the analitical functions, such as sin, cos, etc. But I'd like to take analytical derivatives from asin, atan etc. functions. Are there any R packages providing that features? Thanks. -- Timur.

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

Dear R experts, I looked at the body of, say, `optim' function and found the call to the `.Internal', C optim function. It looks like this: .Internal(optim(par, fn1, gr1, method, con, lower, upper)) On the other hand, the C prototype of optim is: SEXP do_optim(SEXP call, SEXP op, SEXP args, SEXP rho); So, I guess that all the list of parameters passing in R are assigned to

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

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

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

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' ??? ##

Hi all, I am not familiar with writing R extensions. In a C program, I want to create a SEXP and access it in embedded R. How to let the embedded engine know there's a new vector? For example, after creating a SEXP, parsing 'ls()' in embedded R and then evaluating, STRSXP returned will contain the name of the SEXP. Any help would be appreciated. Regards, Spiral [[alternative HTML

Luke, thanks for considering the issue.? I would like to try to separate the problem into two parts, as I _think_ your comments address primarily part 2 below: 1. How can we avoid significant and possibly crippling ?? stalls on error with these non-standard calls. 2. What is the best way to view these non-standard calls. I agree that issue 2. requires further thought and discussion under a

Hi all, im triyng to implement a bayesian model with R and c++. I have a strange problem. I can't reproduce the error with a small script and then i post the original one. The problem is after the line for(MCMC_iter2=0;MCMC_iter2<thin;MCMC_iter2++) For the first 34 iterations all work fine, after, all the simulations of mu_acc_P return an "nan". If i delete the line

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 try to write an extension in C, to get a faster functions. Therefore I have to add an element (vector) to a vector. The command in R is very simple: x = c(x,a) But in C I have the problem to reallocate my vector for getting more space. Everything I tried, I get a "Segmentation fault". So, how can I combine two vectors in C and give the result back to R (return(x))? Thanks