lmomco (version 0.88)

vec2lmom: 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 ($\lambda_1$, $\lambda_2$, $\lambda_3$, $\lambda_4$, $\lambda_5$, $\tau$, $\tau_3$, $\tau_4$, and $\tau_5$). Because in typical practice, the $k \ge 3$ order L-moments are dimensionless ratios ($\tau_3$, $\tau_4$, and $\tau_5$), this function computes $\lambda_3$, $\lambda_4$, $\lambda_5$ from $\lambda_2$ and the ratios. However, typical practice is not set on the use of $\lambda_2$ or $\tau$ as measure of dispersion. Therefore, this function takes an lscale optional logical (TRUE|FALSE) argument--if $\lambda_2$ is provided and lscale=TRUE, then $\tau$ is computed by the function and if $\tau$ is provided, then $\lambda_2$ is computed by the function.

Usage

vec2lmom(vec,lscale)

Arguments

vec

A vector of L-moment values in $\lambda_1$, $\lambda_2$ 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 ($\lambda_2$) or LCV ($\tau$). Default is TRUE, the second value in the first argument is $\lambda_2$.

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.

See Also

lmom.ub, vec2pwm

Examples

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