vec2lmom {lmomco}R Documentation

Convert a Vector of L-moments to a L-moment Object

Description

This function converts a vector of L-moments to a L-moment object of this package. The object is an R list. This function is intended to facilitate the use of L-moments that the user might have from other sources. The first five L-moments are supported (λ_1, λ_2, λ_3, λ_4, λ_5, tau, tau_3, tau_4, and tau_5). Because in typical practice, the k >= 3 order L-moments are dimensionless ratios (tau_3, tau_4, and tau_5), this function computes λ_3, λ_4, λ_5 from λ_2 and the ratios. However, typical practice is not set on the use of λ_2 or tau as measure of dispersion. Therefore, this function takes an lscale optional logical (TRUE|FALSE) argument–if λ_2 is provided and lscale=TRUE, then tau is computed by the function and if tau is provided, then λ_2 is computed by the function.

Usage

vec2lmom(vec,lscale)

Arguments

vec A vector of L-moment values in λ_1, λ_2 or tau, tau_3, tau_4, and tau_5 order.
lscale A logical switch on the type of the second value of first argument. L-scale (λ_2) or LCV (tau). Default is TRUE, the second value in the first argument is λ_2.

Value

An R list is returned.

L1 Arithmetic mean.
L2 L-scale—analogous to standard deviation.
LCV coefficient of L-variation—analogous to coe. of variation.
TAU3 The third L-moment ratio or L-skew—analogous to skew.
TAU4 The fourth L-moment ratio or L-kurtosis—analogous to kurtosis.
TAU5 The fifth L-moment ratio.
L3 The third L-moment.
L4 The fourth L-moment.
L5 The fifth L-moment.

Author(s)

W.H. Asquith

See Also

lmom.ub, vec2pwm

Examples

lmr <- vec2lmom(c(12,0.6,0.34,0.20,0.05),lscale=FALSE)

[Package lmomco version 0.96.3 Index]