lmomco (version 2.2.4)

freq.curve.all: Compute Frequency Curve for Almost All Distributions

Description

This function is dispatcher on top of a select suite of quaCCC functions that compute frequency curves for the L-moments. The term “frequency curves” is common in hydrology and is a renaming of the more widenly known by statisticians term the “quantile function.” The notation CCC represents the character notation for the distribution: exp, gam, gev, gld, glo, gno, gpa, gum, kap, nor, pe3, wak, and wei. The nonexceedance probabilities to construct the curves are derived from nonexceeds.

Usage

freq.curve.all(lmom, aslog10=FALSE, asprob=TRUE, no2para=FALSE, no3para=FALSE, no4para=FALSE, no5para=FALSE, step=FALSE, show=FALSE, xmin=NULL, xmax=NULL, xlim=NULL, ymin=NULL, ymax=NULL, ylim=NULL, aep4=FALSE, exp=TRUE, gam=TRUE, gev=TRUE, gld=FALSE, glo=TRUE, gno=TRUE, gpa=TRUE, gum=TRUE, kap=TRUE, nor=TRUE, pe3=TRUE, wak=TRUE, wei=TRUE,...)

Arguments

lmom

A L-moment object from lmoms, lmom.ub, or vec2lmom.

aslog10

Compute log10 of quantiles---note that

NaNs produced in: log(x, base)

will be produced for less than zero values.

asprob

The R qnorm function is used to convert nonexceedance probabilities, which are produced by nonexceeds, to standard normal variates. The Normal distribution will plot as straight line when this argument is TRUE

no2para

If TRUE, do not run the 2-parameter distributions: exp, gam, gum, and nor.

no3para

If TRUE, do not run the 3-parameter distributions: gev, glo, gno, gpa, pe3, and wei.

no4para

If TRUE, do not run the 4-parameter distributions: kap, gld, aep4.

no5para

If TRUE, do not run the 5-parameter distributions: wak.

step

Shows incremental processing of each distribution.

show

Plots all the frequency curves in a simple (crowded) plot.

xmin

Minimum x-axis value to use instead of the automatic value determined from the nonexceedance probabilities. This argument is only used is show=TRUE.

xmax

Maximum x-axis value to use instead of the automatic value determined from the nonexceedance probabilities. This argument is only used is show=TRUE.

xlim

Both limits of the x-axis. This argument is only used is show=TRUE.

ymin

Minimum y-axis value to use instead of the automatic value determined from the nonexceedance probabilities. This argument is only used is show=TRUE.

ymax

Maximum y-axis value to use instead of the automatic value determined from the nonexceedance probabilities. This argument is only used is show=TRUE.

ylim

Both limits of the y-axis. This argument is only used is show=TRUE.

aep4

A logical switch on computation of corresponding distribution---default is FALSE.

exp

A logical switch on computation of corresponding distribution---default is TRUE.

gam

A logical switch on computation of corresponding distribution---default is TRUE.

gev

A logical switch on computation of corresponding distribution---default is TRUE.

gld

A logical switch on computation of corresponding distribution---default is FALSE.

glo

A logical switch on computation of corresponding distribution---default is TRUE.

gno

A logical switch on computation of corresponding distribution---default is TRUE.

gpa

A logical switch on computation of corresponding distribution---default is TRUE.

gum

A logical switch on computation of corresponding distribution---default is TRUE.

kap

A logical switch on computation of corresponding distribution---default is TRUE.

nor

A logical switch on computation of corresponding distribution---default is TRUE.

pe3

A logical switch on computation of corresponding distribution---default is TRUE.

wak

A logical switch on computation of corresponding distribution---default is TRUE.

wei

A logical switch on computation of corresponding distribution---default is TRUE.

...

Additional parameters are passed to the parameter estimation routines such as parexp.

Value

An extensive R data.frame of frequency curves. The nonexceedance probability values, which are provided by nonexceeds, are the first item in the data.frame under the heading of nonexceeds. If a particular distribution could not be fit to the L-moments of the data; this particular function returns zeros.

References

Hosking, J.R.M., and Wallis, J.R., 1997, Regional frequency analysis---An approach based on L-moments: Cambridge University Press.

See Also

quaaep4, quaexp, quagam, quagev, quagld, quaglo, quagno, quagpa, quagum, quakap, quanor, quape3, quawak, and quawei.

Examples

L <- vec2lmom(c(35612,23593,0.48,0.21,0.11))
Qtable1 <- freq.curve.all(L, step=TRUE, no2para=TRUE, no4para=TRUE)
## Not run: 
# Qtable2 <- freq.curve.all(L, gld=TRUE, show=TRUE)## End(Not run)