lengh of cycle: 2^120,000 memory: 2281*sizeof(double) (about 17K)

typedefs for good boost lagged fibonacci.

See also:

boost::lagged_fibonacci

These generators will quickly generate doubles. Note the memory requirements, because they are somewhat high. I chose the smallest one, and one comparable in speed but higher periodicity without outrageous memory requirements. To use: LLRandLagFib607 foo((U32)time(NULL)); double bar = foo(); lengh of cycle: 2^32,000 memory: 607*sizeof(double) (about 5K)

typedefs for a good boost mersenne twister implementation.

See also:

boost::mersenne_twister

This fairly quickly generates U32 values To use: LLRandMT19937 foo((U32)time(NULL)); U32 bar = foo();

lengh of cycle: 2^19,937-1 memory: about 2496 bytes

Generate a float from [0, RAND_MAX).

Use the boost random number generators if you want a stateful random numbers. If you want more random numbers, use the c-functions since they will generate faster/better randomness across the process.

I tested some of the boost random engines, and picked a good double generator and a good integer generator. I also took some timings for them on linux using gcc 3.3.5. The harness also did some other fairly trivial operations to try to limit compiler optimizations, so these numbers are only good for relative comparisons.

usec/inter algorithm 0.21 boost::minstd_rand0 0.039 boost:lagged_fibonacci19937 0.036 boost:lagged_fibonacci607 0.44 boost::hellekalek1995 0.44 boost::ecuyer1988 0.042 boost::rand48 0.043 boost::mt11213b 0.028 stdlib random() 0.05 stdlib lrand48() 0.034 stdlib rand() 0.020 the old & lame LLRand