Class: ERV::RNG

Inherits:
Object show all
Defined in:
lib/erv/rng.rb

Class Method Summary collapse

Class Method Details

.make_rng(seed = nil) ⇒ Object 



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# File 'lib/erv/rng.rb', line 12

def self.make_rng(seed = nil)
  # if not explicitly provided, seed is taken from the (lower quality)
  # pseudo-random Kernel::rand generator
  if RUBY_PLATFORM == 'java'
    # this is a somewhat ugly workaround in order to avoid ambibuities in
    # the constructor method that will be called (we basically explicit the
    # signature of the constructor that we want to use)
    constructor = org.apache.commons.math3.random.MersenneTwister.java_class.constructor(Java::long)
    rng = constructor.new_instance(seed || Kernel::rand(2**31 - 1))
  else
    rng = seed ?
      GSL::Rng.alloc(GSL::Rng::MT19937, seed) :
      GSL::Rng.alloc(GSL::Rng::MT19937, Kernel::rand(2**31 - 1))
  end
end