GGamma function

Generalized gamma distribution

Provides density, distribution function, quantile function, random value generation, and raw moments of order r for the generalized gamma distribution.

dggamma(x, scale, shape1, shape2, log = FALSE)

pggamma(q, scale, shape1, shape2, lower.tail = TRUE, log.p = FALSE)

qggamma(p, scale, shape1, shape2, lower.tail = TRUE, log.p = FALSE)

rggamma(n, scale, shape1, shape2)

mggamma(r, scale, shape1, shape2)

Arguments

• x, q: vector of quantiles.
• scale, shape1, shape2: scale and shape parameters; the shape arguments cannot be a vectors (must have length one).
• 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 = dggamma,
                args = list(scale = 5,
                            shape1 = .25,
                            shape2 = .75),
                colour = 'royalblue4') +
  labs(x = '',
       y = 'Density') +
  theme_classic()