Module: ML::Util

Defined in:
lib/util/util.rb

Class Method Summary collapse

Class Method Details

.normal_distribution(mean, variance) ⇒ Object 



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# File 'lib/util/util.rb', line 5

def normal_distribution mean, variance
  if @y
    y = @y
    @y = nil
    return y
  end

  theta = 2 * Math::PI * rand
  rho = Math.sqrt(-2 * Math.log(1 - rand))
  scale = variance * rho
  x = mean + scale * Math.cos(theta)
  @y = mean + scale * Math.sin(theta)
  x
end