plotlmrdia {lmomco}R Documentation

Plot L-moment Ratio Diagram

Description

Plot the L-moment ratio diagram of L-skew and L-kurtosis from an L-moment ratio diagram object returned by lmrdia. This diagram is useful for selecting a distribution to model the data. The application of L-moment diagrams is well documented in the literature. This function is intended to function as a demonstration of L-moment diagram plotting. It is expected that users will “roll their own”.

Usage

plotlmrdia(lmr, nopoints=FALSE, nolines=FALSE, nolimits=FALSE,
           nogev=FALSE, noglo=FALSE, nogpa=FALSE, nope3=FALSE, 
           nogno=FALSE, noexp=FALSE, nonor=FALSE, nogum=FALSE, 
           nouni=FALSE, ...)

Arguments

lmr L-moment diagram object from lmrdia.
nopoints If TRUE then point distributions are not drawn.
nolines If TRUE then line distributions are not drawn.
nolimits If TRUE then theoretical limits of L-moments are not drawn.
nogev If TRUE then line of Generalized Extreme Value distribution is not drawn.
noglo If TRUE then line of Generalized Logistic distribution is not drawn.
nogno If TRUE then line of Generalized Normal (log-Normal) distribution is not drawn.
nogpa If TRUE then line of Generalized Pareto distribution is not drawn.
nope3 If TRUE then line of Pearson Type III distribution is not drawn.
noexp If TRUE then point of Exponential distribution is not drawn.
nonor If TRUE then point of Normal distribution is not drawn.
nogum If TRUE then point of Gumbel distribution is not drawn.
nouni If TRUE then point of Uniform distribution is not drawn.
... Additional arguments passed onto the plot function.

Note

This function provides hardwired calls to lines and points to produce the diagram. The plot symbology for the shown distributions is summarized here. The Kappa (four parameter) and Wakeby (five parameter) distributions are not well represented on the diagram as each constitute an area (Kappa) or hyperplane (Wakeby) and not a line (three-parameter distributions) or a point (two-parameter distributions). However, the Kappa demarks the area bounded by the Generalized Logistic (glo) on the top and the theoretical L-moment limits on the bottom.

GRAPHIC TYPE GRAPHIC NATURE
L-moment Limits line width 2 and color 8 (grey)
Generalized Extreme Value line width 1, line type 2 (dash), and color 2 (red)
Generalized Logistic line width 1 and color 3 (green)
Generalized Normal line width 1, line type 2 (dash), and color 4 (blue)
Generalized Pareto line width 1 and color 4 (blue)
Pearson Type III line width 1 and color 6 (purple)
Exponential symbol 16 (filled circle) and color 2 (red)
Normal symbol 15 (filled square) and color 2 (red)
Gumbel symbol 17 (filled triangle) and color 2 (red)
Uniform symbol 18 (filled diamond) and color 2 (red)

Author(s)

W.H. Asquith

References

Asquith, W.H., 1998, Depth-duration frequency of precipitation for Texas: U.S. Geological Survey Water-Resources Investigations Report 98-4044, 107 p.

Hosking, J.R.M., 1990, L-moments–Analysis and estimation of distributions using linear combinations of order statistics: Journal of the Royal Statistical Society, Series B, vol. 52, p. 105-124.

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

Vogel, R.M., and Fennessey, N.M., 1993, L moment diagrams should replace product moment diagrams: Water Resources Research, vol. 29, no. 6, pp. 1745-1752.

See Also

lmrdia

Examples

plotlmrdia(lmrdia())

[Package lmomco version 0.84 Index]