25.1.1 Seeding The RNG

Due to the nature of the RNG and its implementation, it is not necessary to set a seed (the default is 12345). If you wish to change the seed, functions are available. You should only set the seed of the default RNG. Any other RNGs you create are automatically seeded such that they produce independent streams. The range of valid seeds is 1 to MAXINT.

To get non-deterministic behavior, set the seed of the default RNG to 0. This will set the seed based on the current time of day and a counter. This method should not be used to set seeds for independent replications. There is no guarantee that the streams produced by two random seeds will not overlap. The only way to guarantee that two streams do not overlap is to use the substream capability provided by the RNG implementation.


Tom Henderson 2011-11-05