parray {lmomco}R Documentation

Estimate the Parameters of the Rayleigh Distribution

Description

This function estimates the parameters of the Rayleigh distribution given the L-moments of the data in an L-moment object such as that returned by lmom.ub. The relations between distribution parameters and L-moments are

α = frac{2λ_2sqrt{π}}{sqrt{2} - 1}mbox{,}

and

xi = λ_1 - αsqrt{π/2}mbox{.}

Usage

parray(lmom, xi=NULL, checklmom=TRUE)

Arguments

lmom A L-moment object created by lmom.ub or pwm2lmom.
xi The lower limit of the distribution. If xi is known then alternative algorithms are used.
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 tau_4 and tau_3 inequality). However, for some circumstances or large simulation exercises then one might want to bypass this check.

Value

An R list is returned.

type The type of distribution: ray.
para The parameters of the distribution.
source The source of the parameters: “parray”.

Author(s)

W.H. Asquith

References

Hosking, J.R.M., 1986, The theory of probability weighted moments: Research Report RC12210, IBM Research Division, Yorkton Heights, N.Y.

See Also

lmom.ub, lmomray, cdfray, quaray

Examples

lmr <- lmom.ub(rnorm(20))
parray(lmr)

[Package lmomco version 0.96.3 Index]