pdfwak {lmomco}R Documentation

Probability Density Function of the Wakeby Distribution

Description

This function computes the probability density of the Wakeby distribution given parameters (xi, α, β, gamma, and delta) of the distribution computed by pargev. The probability density function of the distribution is

f(x) = [α(1-F)^{β - 1} + gamma(1-F)^{-delta - 1}]^-1mbox{,}

where f(x) is the probability density for quantile x,xi is a location parameter, α and β are scale parameters, and gamma, and delta are shape parameters. The five returned parameters from parwak in order are xi, α, β, gamma, and delta.

Usage

pdfwak(x, para)

Arguments

x A real value.
para The parameters from parwak or similar.

Value

Probability density (f) for x.

Author(s)

W.H. Asquith

References

Hosking, J.R.M. and Wallis, J.R., 1997, Regional frequency analysis—An approach based on L-moments: Cambridge University Press.

Sourced from written communication with Dr. Hosking in October 2007.

See Also

cdfwak, quawak, parwak

Examples

lmr <- vec2lmom(c(1,0.5,.4,.3,.15))
wak <- parwak(lmr)
F <- nonexceeds()
x <- quawak(F,wak)
check.pdf(pdfwak,wak,plot=TRUE)

[Package lmomco version 0.96.3 Index]