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Marsaglia RNG

The Marsaglia generator uses the Marsaglia method to generate a reasonable distribution of random numbers with low computational cost. Marsaglia generators use two random seeds, z and w.

For more information on this algorithm, see the Multiply-with-carry Random Number Generator article at Wikipedia.

Constructor​

// #1 - use random seeds based on time-of-day
// NOTE: this will create variation between runs and between platforms.
MarsagliaRNG::MarsagliaRNG();

// #2 - use explicitly defined seeds
MarsagliaRNG::MarsagliaRNG(unsigned int initial_z, unsigned int initial_w );

Parameters​

  • initial_z (unsigned int) One of two seeds.
  • initial_w (unsigned int) One of two seeds.
  • returns None

generateNextInt32​

int32_t generateNextInt32();

Generate the next signed 32-bit integer.

Parameters​

  • returns (int32_t) The next signed 32-bit integer.

generateNextInt64​

int64_t generateNextInt64();

Generate the next signed 64-bit integer.

Parameters​

  • returns (int64_t) The next signed 64-bit integer.

generateNextUInt32​

uint32_t generateNextUInt32();

Generate the next unsigned 32-bit integer.

Parameters​

  • returns (uint32_t) The next unsigned 32-bit integer.

generateNextUInt64​

uint64_t generateNextUInt64();

Generate the next unsigned 64-bit integer.

Parameters​

  • returns (uint64_t) The next unsigned 64-bit integer

nextUniform​

double  nextUniform();

Generate the next double within the range [0,1).

Parameters​

  • returns (double) The next double within the range [0,1).

restart​

void restart(unsigned int new_z, unsigned int new_w);

Restart the random number generator with new seeds.

Parameters​

  • new_z (unsigned int) One of two seeds.
  • new_w (unsigned int) One of two seeds.
  • returns None

Examples​

Example 1: generateNextInt32()​

SST::RNG::MarsagliaRNG* rng = new SST::RNG::MarsagliaRNG(11, RandomSeed);

int rndNumber;
rndNumber = (int)(rng->generateNextInt32());
rndNumber = (rndNumber & 0x0000FFFF) ^ ((rndNumber & 0xFFFF0000) >> 16);
rndNumber = abs((int)(rndNumber % 3));

Example 2: generateNextUInt32()​

SST::RNG::MarsagliaRNG randomGenerator = new SST::RNG::MarsagliaRNG(11, RandomSeed);

int rndNumber;
int index = randomGenerator.generateNextUInt32() % (numWays-1);

Example 3: generateNextUInt64()​

SST::RNG::MarsagliaRNG rng = new SST::RNG::MarsagliaRNG(11, 201010101);

uint64_t selectA = (rng.generateNextUInt64() % pageCount);
uint64_t selectB = (rng.generateNextUInt64() % pageCount);
#include <sst/core/rng/marsaglia.h>