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module Statistics
module Distribution
class Bernoulli
def self.density_function(n, p)
return if n != 0 && n != 1 # The support of the distribution is n = {0, 1}.
case n
when 0 then 1.0 - p
when 1 then p
end
end
def self.cumulative_function(n, p)
return if n != 0 && n != 1 # The support of the distribution is n = {0, 1}.
case n
when 0 then 1.0 - p
when 1 then 1.0
end
end
def self.variance(p)
p * (1.0 - p)
end
def self.skewness(p)
(1.0 - 2.0*p).to_f / Math.sqrt(p * (1.0 - p))
end
def self.kurtosis(p)
(6.0 * (p ** 2) - (6 * p) + 1) / (p * (1.0 - p))
end
end
end
end
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