parwei {lmomco} | R Documentation |
This function estimates the parameters of the Weibull distribution given
the L-moments of the data in an L-moment object such as that returned by
lmom.ub
. The Weibull distribution is a reverse Generalized Extreme Value distribution. As result, the Generalized Extreme Value algorithms are used for implementation of the Weibull in this package. The relation between the Generalized Extreme Value parameters (xi, α, and kappa) is
kappa = 1/delta mbox{,}
α = β/delta mbox{, and}
xi = zeta - β mbox{.}
These relations are taken from Hosking and Wallis (1997).
parwei(lmom,checklmom=TRUE)
lmom |
A L-moment object created by lmom.ub
or pwm2lmom . |
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. |
An R list
is returned.
type |
The type of distribution: wei . |
para |
The parameters of the distribution. |
source |
The source of the parameters: “parwei”. |
W.H. Asquith
Hosking, J.R.M. and Wallis, J.R., 1997, Regional frequency analysis—An approach based on L-moments: Cambridge University Press.
lmom.ub
, lmomwei
,
cdfwei
, quawei
lmr <- lmom.ub(rnorm(20)) parwei(lmr) lmr <- parwei(lmom.ub(rweibull(3000,1.3,scale=340)-1200)) str(lmr)