parkap: Estimate the Parameters of the Kappa Distribution

Description Usage Arguments Value Author(s) References See Also Examples

Description

This function estimates the parameters of the Kappa distribution given the L-moments of the data in an L-moment object such as that returned by lmoms. The relations between distribution parameters and L-moments are seen under lmomkap.

Usage

1
parkap(lmom, checklmom=TRUE, ...)

Arguments

lmom

An L-moment object created by lmoms or vec2lmom.

checklmom

Should the lmom be checked for validity using the are.lmom.valid function. Normally this should be left as the default and it is very unlikely that the L-moments will not be viable (particularly in the τ_4 and τ_3 inequality). However, for some circumstances or large simulation exercises then one might want to bypass this check.

...

Other arguments to pass.

Value

An R list is returned.

type

The type of distribution: kap.

para

The parameters of the distribution.

source

The source of the parameters: “parkap”.

support

The support (or range) of the fitted distribution.

ifail

A numeric failure code.

ifailtext

A text message for the failure code.

Author(s)

W.H. Asquith

References

Hosking, J.R.M., 1994, The four-parameter kappa distribution: IBM Journal of Reserach and Development, v. 38, no. 3, pp. 251–258.

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

See Also

lmomkap, cdfkap, pdfkap, quakap

Examples

1
2
lmr <- lmoms(rnorm(20))
parkap(lmr)

Example output

$type
[1] "kap"

$para
   xi alpha kappa     h 
    0     0     0     0 

$source
[1] "parkap"

$support
[1] NA NA

$ifail
[1] 2

$ifailtext
[1] "TAU3 and TAU4 are above Generalized Logistic line."

lmomco documentation built on Nov. 17, 2017, 7:25 a.m.