Using the Various Random Number Services

Description

I3RandomService is patterned off of ROOT’s TRandom, and provides access to random numbers drawn from several possible distributions. The I3RandomService is an abstract interface, which can be serviced by any of several implementations.

The advantage of having an I3RandomService interface between us and the random number generator. We can dynamically switch between any implementations of I3RandomSerivce.

Currently there are three implementations of this interface:

• I3GSLRandomService - uses the gnu scientific library to generate random numbers. It is added to the framework with the I3GSLRandomServiceFactory. It takes a single integer parameter Seed which is given to gsl as the seed for the random number sequence.

• I3SPRNGRandomService - uses the SPRNG library to produce independent streams of pseudo-random numbers for distributed computation.

• I3MTRandomService - Uses the c++11 random number interface for the widely used MT19937 algorithm. Can take a single int as a seed or a sequence of ints of arbitrary length for distributed computing. It can be added to the context with I3MTRandomServiceFactory or the python class icecube.phys_services.I3MTRandomService.

The original I3TRandomService implementation was removed due to the fact that it was unused.