plot.gev: Plot GEV model diagnostics

In dannyjameswilliams/danielR: Collection of Danny's R Code

Description

Plot the probability and the quantile-quantile plot for the GEV distribution, for a model fit by gev_fit.

Usage

## S3 method for class 'gev'
plot(x, ...)

Arguments

x	object of class "gev" fit by gev_fit
...	further arguments for plotting (will apply to both plots)

Details

The probability plot plots the model calculated

G(z_i) = \exp \{ - ( 1 + ξ (z_i - μ)/σ)^{-1/ξ} \}

against the empirical

H(z_i) = i / (m + 1).

If the model is a good fit, these should be approximately equal, and so the points plotted should lie on a diagonal line.

The quantile-quantile plot plots

G^{-1} = μ - (σ / ξ) (1 - (- log(i/(m+1)))^{-ξ} )

against the observed maxima z_i. Similar to the probability plot, this should also lie on the diagonal line for a good fit, as these points should be approximately equal.

Value

printed elements

dannyjameswilliams/danielR documentation built on Feb. 1, 2021, 6:39 p.m.