rabauke / trng4

state of the art C++ pseudo-random number generator library for sequential and parallel Monte Carlo simulations
https://www.numbercrunch.de/trng/
BSD 3-Clause "New" or "Revised" License
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c-plus-plus computational-finance computational-physics hpc library monte-carlo-methods pseudo-random-generator

TRNG - A modern C++ pseudo random number generator library

Key features

Example

TRNG classes can be used as a drop-in replacement for classes declared in the random header file of the C++ standard library. In addition, the TRNG random number generators provide jump and split methods for constructing independent streams of pseudo random numbers for parallel Monte Carlo simulations. The following code illustrates the use of TRNG pseudo random number generators for the parallel Monte Carlo calculation of pi.

#include <cstdlib>
#include <iostream>
#include <omp.h>
#include <trng/yarn2.hpp>
#include <trng/uniform01_dist.hpp>

int main() {
  const long samples{1000000l};  // total number of points in square
  long in{0l};                   // number of points in circle
  // distribute workload over all processes and make a global reduction
#pragma omp parallel reduction(+ : in) default(none)
  {
    trng::yarn2 r;                          // random number engine
    const int size{omp_get_num_threads()};  // get total number of processes
    const int rank{omp_get_thread_num()};   // get rank of current process
    trng::uniform01_dist<> u;               // random number distribution
    r.jump(2 * (rank * samples / size));    // jump ahead
    // throw random points into square
    for (long i{rank * samples / size}; i < (rank + 1) * samples / size; ++i) {
      const double x{u(r)}, y{u(r)};  // choose random x- and y-coordinates
      if (x * x + y * y <= 1.0)       // is point in circle?
        ++in;                         // increase thread-local counter
    }
  }
  // print result
  std::cout << "pi = " << 4.0 * in / samples << std::endl;
  return EXIT_SUCCESS;
}

Documentation

For installation instructions and further documentation see the trng.pdf file in the doc directory.