GEV function

Generalized extreme value distribution

Provides density, distribution function, quantile function, and random value generation, for the generalized extreme value distribution.

dgev(x, loc, scale, shape, log = FALSE)

pgev(q, loc, scale, shape, lower.tail = TRUE, log.p = FALSE)

qgev(p, loc, scale, shape, lower.tail = TRUE, log.p = FALSE)

rgev(n, loc, scale, shape)

mgev(r, loc, scale, shape)

Arguments

• x, q: vector of quantiles.
• loc, scale, shape: location, scale and shape parameters.
• log, log.p: logical; if TRUE, probabilities p are given as log(p).
• lower.tail: logical; if TRUE (default), probabilities are $P[X \le x]$ otherwise, $P[X > x]$.
• p: vector of probabilities.
• n: number of observations. If length(n) > 1, the length is taken to be the number required.
• r: raw moment order

Examples

## plot the density

ggplot(data.frame(x = c(0, 20)),
       aes(x)) +
  stat_function(fun = dgev,
                args = list(loc = 1,
                            scale = .5,
                            shape = .15),
                colour = 'royalblue4') +
  labs(x = '',
       y = 'Density') +
  theme_classic()