rfa: Regional Frequency Analysis

Description

This function uses J.R.M. Hosking's package produce an object of class 'rfd', containing the specification of the regional frequency distribution.

Usage

rfa(lflist, n = 7, event = 100, dist = c("wei", "gev", "ln3", "gum", "pe3"))

Value

An object of class "rfd", containing the specification of the regional frequency distribution: It is a list with the following elements:

dist: The character string dist.
para: Vector containing the parameters of the fitted regional distribution.
qfunc: The quantile function of distribution dist. It is a function that takes a single argument, a vector of probabilities, and returns a vector of quantiles.
rmom: The regional average \(L\)-moments.
index: Index flood values at each site. This is a named vector whose values are the index flood values at each site, from regdata[[3]], and whose names are the site names, from regdata[[1]].

Arguments

lflist: A list of 'lfobj's.
n: MAM-n is used (e.g. n=7 means MAM7).
event: A value for T, e.g. event = 100 means the 100 years extreme low flow event.
dist: A vector of distribution to fit, the names are according to Hosking's in his lmom package. Can be an of "wei", "gev", "ln3", "gum", "pe3".

References

Gustard, A. & Demuth, S. (2009) (Eds) Manual on Low-flow Estimation and Prediction. Operational Hydrology Report No. 50, WNO-No. 1029, 136p. https://library.wmo.int/doc_num.php?explnum_id=7699

Examples

Run this code

data(ngaruroro)
# Toy example to get some more "rivers"
seventies <- subset(ngaruroro, hyear %in% 1970:1979)
eighties <- subset(ngaruroro, hyear %in% 1980:1989)
nineties <- subset(ngaruroro, hyear %in% 1990:1999)

toyrfa <- rfa(list(seventies,eighties,nineties), n=3,dist = "gev")

require(lmomRFA)
regquant(c(1/1000,1/100),toyrfa)
sitequant(1/100,toyrfa)