Random123/gsl_microrng.h File Reference

#include <gsl/gsl_rng.h>
#include <string.h>

Go to the source code of this file.

Defines
#define	GSL_MICRORNG(NAME, CBRNGNAME, BITS)

---

Define Documentation

#define GSL_MICRORNG	(		NAME,
			CBRNGNAME,
			BITS
	)

The macro: GSL_MICRORNG(NAME, CBRNGNAME, BITS) is the GSL analog analog of the C++ r123::MicroURNG template. It declares a gsl_rng type named gsl_rng_NAME which uses the underlying CBRNGNAME and can be invoked a limited number of times between calls to NAME_reset.

When the underlying CBRNG's ctr_t is an r123arrayNxW, BITS must be less than W, and the gsl_rng_NAME may called up to N*2^BITS times between calls to NAME_reset.

NAME_reset takes a gsl_rng_NAME type, a counter and a key as arguments. It restarts the micro-rng with a new base counter and key.

Note that you must call NAME_reset before the first use of a gsl_rng. NAME_reset is not called automatically by gsl_rng_alloc().

   #include <Random123/threefry.h>
   #include <Random123/gsl_microrng.h> // this file
   GSL_MICRORNG(microcbrng, threefry4x64, 20)   // creates gsl_rng_microcbrng

   int main(int argc, char** argv) {
        gsl_rng *r = gsl_rng_alloc(gsl_rng_microcbrng);
        threefry4x64_ctr_t c = {{}};
        threefry4x64_key_t k = {{}};

        for (...) {
            c.v[0] = ??; //  some application variable
            microcbrng_reset(r, c, k);
            for (...) {
                // gaussian calls r several times.  It is safe for
                // r to be used upto 2^20 times in this loop
                something[i] = gsl_ran_gaussian(r, 1.5);
            }
        }
   }