`scipy.stats._continuous_distns:exponnorm_gen`

source: /scipy/stats/_continuous_distns.py :2162

Signature

   class     exponnorm_gen (    momtype    =  1   ,    a    =  None   ,    b    =  None   ,    xtol    =  1e-14   ,    badvalue    =  None   ,    name    =  None   ,    longname    =  None   ,    shapes    =  None   ,    seed    =  None     )

Members

Summary

An exponentially modified Normal continuous random variable.

Extended Summary

Also known as the exponentially modified Gaussian distribution ^[1].

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Notes

The probability density function for exponnorm is:

f (x, K) = \frac{1}{2 K} exp (\frac{1}{2 K ^{2}} - x / K) erfc (- \frac{x - 1/ K}{2})

where $x$ is a real number and $K > 0$ .

It can be thought of as the sum of a standard normal random variable and an independent exponentially distributed random variable with rate 1/K.

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An alternative parameterization of this distribution (for example, in the Wikipedia article ^[1]) involves three parameters, $μ$ , $λ$ and $σ$ .

In the present parameterization this corresponds to having loc and scale equal to $μ$ and $σ$ , respectively, and shape parameter $K = 1/ (σ λ)$ .

Aliases

scipy.stats._continuous_distns.exponnorm_gen