fisk_shape: First stage estimate for beta in the Fisk distribution

In Shakeel95/bioFlex: Estimation and model selection for strictly positive heavy tailed data, using flexible parametric distributions

Description

Computes the method of moments estimate for the shape parameter in the Fisk dustribution.

Usage

fisk_shape(x, lower_bound = 0.001, upper_bound = pi/2)

Arguments

x	A numeric vector of i.i.d. observations presumed to be draws from a Fisk distribution.
lower_bound	Lower bound in solution pace of the trigonometric equation used to find the value of beta. Ideally zero since as the solution will always be between zero and pi/2, however since the function must be defined at both endpoints zero cannot be used. By default the parameter is set to 0.001.
upper_bound	Upper bound in solution pace of the trigonometric equation used to find the value of beta. By default the parameter is set to pi/2.

References

"Solving Log-Logistic Distribution Parameters From Moments." Cross Validate. N.p., 2017. Web. 11 Aug. 2018.

Shakeel95/bioFlex documentation built on March 3, 2020, 11:27 a.m.