similar to: Rcpp with OpenMP - Need example Makevars

Hi everybody, I'm trying to develop an R package with Fortran and OpenMP. I wrote a simple hello world but I'm not able to set the number of threads. I found this old email chain <http://r.789695.n4.nabble.com/Set-the-number-of-threads-using-openmp-with-C-td2284685.html> and I tried to set my compile instructions accordingly but i had no luck. *This is my makevars:*

I got this to work on Linux but it is not working on Windows. *My understanding is that this should also work on windows, is that correct?* If so, what should I do? differently? To get it to work on Linux, I modified my R script as follows: #' OpenMP Hello World #' #' @param nthreads The number of threads that you want to use #' @example #' hello(nthreads=2) #' @export

Hi everybody! Could somebody help me with the following? I'm trying to run a simple Hello World code in openmp using .C function. The C code i have is: #include <omp.h> #include <stdio.h> #include <R.h> void hello_omp(int *n) { int th_id, nthreads; omp_set_num_threads(*n); #pragma omp parallel private(th_id) { th_id = omp_get_thread_num();

Dears, I am writing a code in Fortran using OpenMP directives. When compiling the code in gfortran 4.4 does not occur any problem. When compiling the code in gfortran 4.6, an error message appears. In other compilers the error does not occur. A small example. ## Code in Fortran        subroutine hello()        implicit none        integer :: nthreads, tid        integer ::

Hi, I am using LLVM 3.6.1 to test the following code: #include <omp.h> #include <stdio.h> #include <stdlib.h> int main() { int tid, nthreads; #pragma omp parallel sections private(nthreads, tid) { #pragma omp section { tid = omp_get_thread_num(); printf("Hello, tid = %d\n ", tid); } #pragma omp section { tid = omp_get_thread_num();

Dirk, thank you a thousand times. Indeed, src/Makevars was wrong. I modified Makevars so that now looks like the below and the package now compiled and linked properly. CXX_STD = CXX11 PKG_LIBS += $(SHLIB_OPENMP_CXXFLAGS) $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS) $(shell ${R_HOME}/bin/Rscript -e "RcppParallel::RcppParallelLibs()") PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS) -I../inst/include

When I install an R package with cpp codes such as rrcov via CRAN (under R 3.1.1, using no Makevars file and under Ubuntu 14.04 using GCC 4.8), the cpp code is compiled with the -o3 flag (in fact, looking at the Makeconf file this seem to again be the default since R 3.1.1) But when I install my own package via CRAN it is compiled with the -o2 flag. My questions are what is causing my

Hi all, i want to replace a bunch of Apple Xserves with Xraids and HFS+ (brr) by Sun x4200 with SAS-Jbods and ZFS. The application will be the Helios UB+ fileserver suite. I installed the latest Solaris 10 on a x4200 with 8gig of ram and two Sun SAS controllers, attached two sas-jbods with 8 SATA-HDDs each und created a zfs pool as a raid 10 by doing something like the following: [i]zpool create

Hi, I can not install packages from source which links to RcppArmadillo on Ubuntu 20.04 (after upgrading from 18.04). The following problem occurs: ** testing if installed package can be loaded from temporary location Error: package or namespace load failed for 'myPackage' in dyn.load(file, DLLpath = DLLpath, ...): unable to load shared object

I am trying to parallelize part of a C function that is called from R (via .C) using OpenMP's "parallel for" pragma. I get mixed results: some runs finish with no problem, but some lead to R crashing after issuing a long error message involving memory violations. I found this post, which describes how a .Call() function can be made to avoid crashing R by raising the stack limit:

Hi, I experience surprisingly large timing differences for the multiplication of matrices of the same dimension. An example is given below. How can this be explained? I posted the question on Stackoverflow: https://stackoverflow.com/questions/58886111/r-why-is-matrix-product-slower-when-matrix-has-very-small-values Somebody could reproduce the behavior but I did not get any useful explanations

Can you send the IR you are using? Volkan On Thu, Oct 8, 2015 at 6:28 AM Erdem Derebaşoğlu < erdemderebasoglu at hotmail.com> wrote: > Thanks. I enabled my pass. I have one resolved issue though: > MachineMemOperand::getAddrSpace() always returns zero. How can I use it to > distinguish private memory accesses? > > Erdem > > ------------------------------ > From:

I didn't do the compile; is there a way to check whether that was used? If not, I'll inquire with our sysadmin and report back. In any case, my suggestion was motivated by the fact that some parts of R use OpenMP while others do not, in the hope that the former could have their OpenBLAS omelet without breaking the OpenMP eggs, so to speak. On 01/09/2018 06:41 PM, Keith O'Hara

Please pardon my ignorance, but doesn't OpenBLAS still not always play nicely with multi-threaded OpenMP? (for example, don't race conditions sometimes crop up)? If so, it might be nice to have the ability to temporarily disable multi-threaded OpenMP (effectively: omp_set_num_threads(1)) for the duration of operations using OpenBLAS. Regards Ben > Julia using OpenBLAS is *very*

On Apr 17, 2014, at 2:04 PM, Chandler Carruth <chandlerc at google.com> wrote: > On Thu, Apr 17, 2014 at 1:27 PM, Justin Bogner <mail at justinbogner.com> wrote: > Chandler Carruth <chandlerc at google.com> writes: > > if (thread-ID != main's thread-ID && shard_count < std::min(MAX, NUMBER_OF_CORES)) { > > shard_count = std::min(MAX,

Dears, I am writing a code in Fortran using OpenMP directives. When compiling the code in gfortran 4.4 does not occur any problem. When compiling the code in gfortran 4.6, an error message appears. In other compilers the error does not occur. A small example. ## Code in Fortran        subroutine hello()        implicit none        integer :: nthreads, tid        integer ::

Greeting All I am using Filebench benchmark in an "Interactive mode" to test ZFS performance with randomread wordload. My Filebench setting & run results are as follwos ------------------------------------------------------------------------------------------ filebench> set $filesize=5g filebench> set $dir=/hdd/fs32k filebench> set $iosize=32k filebench> set

On Fri, Apr 18, 2014 at 11:13 AM, Dmitry Vyukov <dvyukov at google.com> wrote: > Hi, > > This is long thread, so I will combine several comments into single email. > > > >> - 8-bit per-thread counters, dumping into central counters on overflow. > >The overflow will happen very quickly with 8bit counter. > > Yes, but it reduces contention by 256x (a thread

Thanks Keith. We checked, and indeed libopenblas is not linked against libomp nor libgomp. We suspect this is because we used conda to install R and OpenBLAS. So I guess we should be barking up the conda tree instead? By the way, I also noticed on my home machine (Ubuntu), /usr/lib/libopenblas.so.0 is also not linked against those, for what that's worth. Regards, Ben On 01/10/2018 12:04

Dear R-Developers, I just started learning how to use Rcpp. Earlier while using it, I encountered an error as shown below: file74d8254b96d4.cpp: In function ‘Rcpp::NumericVector foo(Rcpp::NumericVector, Rcpp::NumericVector, Rcpp::NumericVector, Rcpp::Function, Rcpp::Function)’: file74d8254b96d4.cpp:10: error: invalid operands of types ‘SEXPREC*’ and ‘R_len_t’ to binary ‘operator/’ make: ***