Random Number Generators

See also file common/rand.h

Measuring the time consumption of program sections are often of great interest. The Stxxl comes with several build-in pseudo random number generators as shown below:

stxxl::random_number32 rand32;  // integer values in [0, 2^32)
stxxl::random_number64 rand64;  // integer values in [0, 2^64)
stxxl::random_uniform_slow urand_slow;  // uniform values in [0.0, 1.0)
stxxl::random_uniform_fast urand_fast;  // uniform values in [0.0, 1.0)
stxxl::random_number<> n_rand;  // integer values in [0,N)

unsigned int random32 = rand32();
stxxl::uint64 random64 = rand64();
double urandom_slow = urand_slow();
double urandom_fast = urand_fast();
unsigned int n_random = n_rand(123456789);

STXXL_MSG("random 32 bit number: " << random32);
STXXL_MSG("random 64 bit number: " << random64);
STXXL_MSG("random number between [0.0, 1.0) (slow): " << urandom_slow);
STXXL_MSG("random number between [0.0, 1.0) (fast): " << urandom_fast);
STXXL_MSG("random number between [0,123456789): " << n_random);