random.h File Reference

Engine-boundary C API for the engine's PRNG and rational / real / complex random draws. More...

#include "engine-includes.hpp"

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Functions
void	rawRandomInitialize ()
void	rawSetRandomSeed (gmp_ZZ newseed)
void	rawSetRandomMax (gmp_ZZ)
unsigned long	rawRandomULong (unsigned long max)
int32_t	rawRandomInt (int32_t max)
void	rawSetRandomInteger (mpz_ptr result, gmp_ZZ maxN)
gmp_ZZ	rawRandomInteger (gmp_ZZ maxN)
void	rawSetFareyApproximation (mpq_ptr result, gmp_RR x, gmp_ZZ height)
gmp_QQ	rawFareyApproximation (gmp_RR x, gmp_ZZ height)
gmp_QQ	rawRandomQQ (gmp_ZZ height)
void	rawSetRandomQQ (mpq_ptr result, gmp_ZZ height)
gmp_RR	rawRandomRRUniform (unsigned long prec)
gmp_RR	rawRandomRRNormal (unsigned long prec)
gmp_CC	rawRandomCC (unsigned long prec)
void	randomMpfr (mpfr_t result)
gmp_RRi	rawRandomRRi (unsigned long prec)
void	rawSetRandomRRi (mpfi_ptr result)
gmp_CCi	rawRandomCCi (unsigned long prec)
double	randomDouble ()
int	system_randomint ()

Detailed Description

Engine-boundary C API for the engine's PRNG and rational / real / complex random draws.

Note

AI-generated documentation. Verify against the source before relying on it.

Declares the extern "C" entry points that seed and consult the engine's pseudo-random number generator: rawRandomInitialize resets it, rawSetRandomSeed(gmp_ZZ) plants a reproducible seed, rawSetRandomMax(gmp_ZZ) installs the default upper bound for integer draws, and the typed draws cover every coefficient flavour the engine supports — rawRandomULong / rawRandomInt for sub-word integers, rawRandomInteger / rawSetRandomInteger for big integers (the latter writing through an mpz_ptr to avoid the garbage-collected allocation), rawRandomQQ / rawSetRandomQQ for rationals with bounded numerator and denominator, rawRandomRRUniform / rawRandomRRNormal / rawRandomCC for arbitrary-precision real and complex variates, rawRandomRRi / rawSetRandomRRi / rawRandomCCi for interval variants, the MPFR-direct randomMpfr, and randomDouble / system_randomint for the C fast paths. Farey-approximation helpers (rawFareyApproximation, rawSetFareyApproximation) sit here since they reuse the same big-integer height parameter.

The PRNG state is a triple of file-scope statics in random.cpp (the GMP gmp_randstate_t state, the int32_t RandomSeed Schrage-style seed for rawRandomInt, and the mpz_t maxHeight default upper bound) — there is no thread_local or mutex protection, so single-threaded runs are reproducible from a given seed but concurrent threads share state and a parallel run is neither race-free nor reproducible. The aring-* coefficient backends pick this up via randomDouble / rawRandomInteger.

See also

random.cpp

engine-includes.hpp

Definition in file random.h.