Method: ERV::GammaDistribution#initialize

Defined in:
lib/erv/gamma_distribution.rb

#initialize(opts = {}) ⇒ GammaDistribution

Returns a new instance of GammaDistribution.

Raises:

  • (ArgumentError) 


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# File 'lib/erv/gamma_distribution.rb', line 16

def initialize(opts={})
  super(opts)

  raise ArgumentError unless opts[:scale] and opts[:shape]
  @scale = opts[:scale].to_f
  @shape = opts[:shape].to_f

  raise ArgumentError, "scale parameter must be greater than zero!" unless @scale > 0.0
  raise ArgumentError, "shape parameter must be greater than zero!" unless @shape > 0.0

  @mean = @shape / @scale
  @variance = @shape / (@scale ** 2)
end