vec2lmom {lmomco} | R Documentation |
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.
vec2lmom(vec,lscale)
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. |
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. |
W.H. Asquith
lmr <- vec2lmom(c(12,0.6,0.34,0.20,0.05),lscale=FALSE)