`scipy.stats._continuous_distns:crystalball_gen`

source: /scipy/stats/_continuous_distns.py :11618

Signature

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

Members

Summary

Crystalball distribution

Extended Summary

%(before_notes)s

Notes

The probability density function for crystalball is:

f (x, β, m) = {N exp (- x^{2} /2), N A (B - x)^{- m} for x > - β for x \leq - β

where $A = (m /∣ β ∣)^{m} exp (- β^{2} /2)$ , $B = m /∣ β ∣ - ∣ β ∣$ and $N$ is a normalisation constant.

crystalball takes $β > 0$ and $m > 1$ as shape parameters. $β$ defines the point where the pdf changes from a power-law to a Gaussian distribution. $m$ is the power of the power-law tail.

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Aliases

scipy.stats._continuous_distns.crystalball_gen