loglogistic4_fn {drda}R Documentation

4-parameter log-logistic function

Description

Evaluate at a particular set of parameters the 4-parameter log-logistic function.

Usage

loglogistic4_fn(x, theta)

Arguments

x

numeric vector at which the function is to be evaluated.

theta

numeric vector with the four parameters in the form c(alpha, delta, eta, phi).

Details

The 4-parameter log-logistic function ⁠f(x; theta)⁠ is defined here as

⁠g(x; theta) = x^eta / (x^eta + phi^eta)⁠ ⁠f(x; theta) = alpha + delta g(x; theta)⁠

where x >= 0, theta = c(alpha, delta, eta, phi), eta > 0, and phi > 0.

Value

Numeric vector of the same length of x with the values of the log-logistic function.


[Package drda version 2.0.3 Index]