Class: Statistical::Rng::TwoPoint

Inherits:
Object
  • Object
show all
Defined in:
lib/statistical/rng/two_point.rb

Overview

Random number generator to model the two point distribution used for working with problem where the state space has only two points with distinct probabilities

Direct Known Subclasses

Bernoulli

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(dobj = nil, seed = Random.new_seed) ⇒ TwoPoint

Companion RNG class for the two-point distribution. Requires a distrbution object of the corresponding type. Defaults to the standard bernoulli if no arguments are given

Author:

  • Vaibhav Yenamandra



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# File 'lib/statistical/rng/two_point.rb', line 22

def initialize(dobj = nil, seed = Random.new_seed)
  unless dobj.nil? || dobj.is_a?(Statistical::Distribution::TwoPoint)
    raise TypeError,
          "Expected Distribution object or nil, found #{dobj.class}"
  end
  dobj = Statistical::Distribution::TwoPoint.new if dobj.nil?
  @generator = Random.new(seed)
  @sdist = dobj
  @p = dobj.p
  @q = dobj.q
  @states = dobj.states
end

Instance Attribute Details

#generator ⇒ Object (readonly)

Returns the value of attribute generator.



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# File 'lib/statistical/rng/two_point.rb', line 10

def generator
  @generator
end

#p ⇒ Object (readonly)

Returns the value of attribute p.



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# File 'lib/statistical/rng/two_point.rb', line 10

def p
  @p
end

#q ⇒ Object (readonly)

Returns the value of attribute q.



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# File 'lib/statistical/rng/two_point.rb', line 10

def q
  @q
end

#states ⇒ Object (readonly)

Returns the value of attribute states.



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# File 'lib/statistical/rng/two_point.rb', line 10

def states
  @states
end

Instance Method Details

#rand ⇒ Object

Return the next random number from the sequence following the given distribution

Returns:

  • next random number in the sequence



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# File 'lib/statistical/rng/two_point.rb', line 39

def rand
  return @sdist.quantile(@generator.rand)
end

#support ⇒ Object

The support set over which the distribution exists



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# File 'lib/statistical/rng/two_point.rb', line 62

def support
  @sdist.support
end

#type ⇒ Object

Return the type of the source distribution

Returns:

  • source distribution’s type



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# File 'lib/statistical/rng/two_point.rb', line 57

def type
  @sdist.class
end