The inverse Gaussian distribution, also known as the Wald distribution, is the distribution over
with probability density function
and distribution function given by
(1)
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(2)
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where
is the mean and
is a scaling parameter.
The inverse Gaussian distribution is implemented in the Wolfram Language as InverseGaussianDistribution[mu, lambda].
The th
raw moment is given by
(3)
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where
is a modified Bessel function
of the second kind, giving the first few as
(4)
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(5)
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(6)
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Using
gives a recursion relation for the raw moments as
(7)
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The first few central moments are
(8)
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(9)
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(10)
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The cumulants are given by
(11)
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The variance, skewness, and kurtosis excess are given by
(12)
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(13)
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(14)
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