Johnson SU distribution

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Johnson S_{U}
Parameters γ, ξ, σ > 0, λ > 0 (real)
Support -\infty {\text{ to }}+\infty
CDF \Phi (\gamma +\sigma \sinh ^{{-1}}z)
Mean \chi -\lambda \exp {{\frac  {\sigma ^{{-2}}}{2}}}\sinh({\frac  {\gamma }{\sigma }})
Variance {\frac  {\lambda ^{2}}{2}}(\exp {(\sigma ^{{-2}})}-1)(\exp {(\sigma ^{{-2}})}\cosh ^{{2}}{({\frac  {2\gamma }{\sigma }})}+1)

The Johnson S_{U} distribution is a four-parameter family of probability distributions first investigated by N. L. Johnson in 1949.[1] It is closely related to the normal distribution.

Generation of random variables

Let U be a random variable that is uniformly distributed on the unit interval [0, 1]. Johnson S_{U} random variables can be generated from U as follows:

x=\lambda \sinh \left({\frac  {1}{\sigma }}\Phi ^{{-1}}(U)-\gamma \right)+\chi

where Φ is the cumulative distribution function of the normal distribution.

References

  1. Johnson, N. L. (1949) Systems of frequency curves generated by methods of translation. Biometrika 36: 149–176 JSTOR 2332539

Additional reading

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