plot.gev: Plot GEV model diagnostics

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

Plot GEV model diagnostics

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 + \xi (z_i - \mu)/\sigma)^{-1/\xi} \}

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} = \mu - (\sigma / \xi) (1 - (- log(i/(m+1)))^{-\xi} )

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 Aug. 20, 2023, 3:25 a.m.