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GLmom (version 1.3.1)

Generalized L-Moments Estimation for Extreme Value Distributions

Description

Provides generalized L-moments estimation methods for the generalized extreme value ('GEV') distribution. Implements both stationary 'GEV' and non-stationary 'GEV11' models where location and scale parameters vary with time. Includes various penalty functions ('Martins'-'Stedinger', Park, Cannon, 'Coles'-Dixon) for shape parameter regularization. Also provides model averaging estimation ('ma.gev') that combines MLE and L-moment methods with multiple weighting schemes for robust high quantile estimation. The 'GLME' methodology is described in Shin et al. (2025a) . The non-stationary L-moment method is based on Shin et al. (2025b) . The model averaging method is described in Shin et al. (2026) . See also 'Hosking' (1990) for L-moments theory and 'Martins' and 'Stedinger' (2000) for penalized likelihood methods.

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install.packages('GLmom')

Monthly Downloads

125

Version

1.3.1

License

GPL (>= 3)

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Maintainer

Yonggwan Shin

Last Published

February 27th, 2026

Functions in GLmom (1.3.1)

cov.interp

Interpolate missing covariance matrices across submodels
glme.like

Calculate the likelihood for Generalized L-moments estimation of GEV distribution
movave

Moving average smoother for quantiles and weights
mle.gev.CD

Coles-Dixon Penalized MLE for GEV
nsgev

Non-stationary GEV Parameter Estimation
pk.norm.stnary

Normal preference function for shape parameter (stationary GEV)
pk.beta.stnary

Beta preference function for stationary GEV
obj.lme.gev11

L-moment distance function for GEV11 model
is.odd.me

Check if a number is odd
lme.boots

L-moment estimation with bootstrap standard errors
streamflow

Streamflow Data
set.prior

Set BMA prior distribution for candidate shape parameters
set.para.model

Set parameters based on non-stationary model type
emp.prior

Empirical prior for BMA based on MLE and LME
sel.para_all

Select best parameters based on goodness-of-fit
glme.gev

Generalized L-moments estimation for generalized extreme value distribution
glme.gev11

Generalized L-moments estimation for non-stationary GEV11 model
init.glme

Initialize random starting values for GLME optimization
quagev.NS

Quantile function for non-stationary GEV models
init.glme.gev11

Initialize parameters for multi-start GEV11 optimization
qns.gev_all

Quantile function for non-stationary GEV (return period input)
gev.xilik

GEV negative log-likelihood with fixed xi
wlik.xifix

Likelihood-based weights with fixed xi
wls.gev11

Weighted least squares core estimation for GEV11
gof.ene_all

Goodness-of-fit based on exceedance counts
magev.ksensplot

K Sensitivity Plot for MAGEV
pargev.kfix

GEV parameter estimation with fixed shape parameter
optim.glme.gev11

Multi-start optimization for GEV11 model
magev.qqplot

Q-Q Diagnostic Plot for MAGEV
magev.rlplot

Return Level Plot for MAGEV
gev.xilik2

GEV negative log-likelihood with fixed xi (wrapper)
init.gevmax

Initialize parameters for GEV MLE estimation
haenam

Haenam Maximum Rainfall Data
ma.gev

Model Averaging for GEV High Quantile Estimation
gado.prop_11

Comprehensive Non-stationary GEV Estimation
new.kpar2

Adaptively expand or prune candidate xi set
weight.com

Compute model averaging weights
rcd

Revised Coles-Dixon prior function
time.m.gev11

Time-varying moment estimation (GN16 method)
remle.gev

Restricted MLE for GEV (Mixed Estimation)
make.qmax.gev11

Create maximum residual series for GEV11 model
gev.rl.delta

MLE with return level and delta method SE
gev.xifix.sing

MLE for GEV with fixed shape parameter (single candidate)
lmoms.md.park

Modified L-moments calculation with optional trimming
prior.beta.stnary.ma

Beta prior for model averaging
strup.glme.gev11

Strup WLS estimation for GEV11
qns.gev11

Quantile function for GEV11 model
surrogate

Find surrogate GEV parameters for model-averaged quantiles
pargev.xifix

GEV parameter estimation with fixed shape parameter (MAGEV internal)
nllh.glme.gev11

GLME objective function for GEV11 model (mu0, sigma0, xi optimization)
pk.beta.ns

Beta preference function for non-stationary GEV
PrescottW

Prescott-Walden expected information matrix for GEV with fixed xi
MS_pk

Martins-Stedinger prior function
com.prdist

Compute generalized L-moment distance probabilities
dist.noboot

Fit submodels and compute distance-based probabilities
cand.xi

Select candidate shape parameter values for model averaging
delta.gev

Delta method variance and cross-covariance for GEV quantiles
PhliuAgromet

Phliu Agrometeorological Station Data
Befun

Beta function integrand for penalty calculation
comp.prof.ci

Compute profile likelihood confidence intervals
gev.profxi.mdfy

Modified profile likelihood for GEV shape parameter
asymp.var

Asymptotic variance of model-averaged quantile estimates
cons.MatC

Construct covariance matrix C for model averaging SE
bangkok

Bangkok Maximum Rainfall Data
cd.hos

Coles-Dixon Penalty Function
gev.max

MLE for GEV distribution using constrained optimization
Trehafod

Trehafod River Flow Data
cov.dir

Dirichlet covariance matrix for weights
gev11.GLD

Calculate GLD covariance for GEV11 model
ginit.xifix

Initialize parameters for GEV with fixed xi