R/GammaSupp.R

In actuar: Actuarial Functions and Heavy Tailed Distributions

### actuar: Actuarial Functions and Heavy Tailed Distributions
###
### Definition of the {m,lev,mgf}gamma functions to compute raw and
### limited moments, and the moment generating function for
### the Gamma distribution (as defined in R)
###
### See Chapter 17 of Johnson & Kotz, Continuous univariate
### distributions, volume 1, Wiley, 1970
###
### AUTHORS: Mathieu Pigeon, Christophe Dutang,
### Vincent Goulet <vincent.goulet@act.ulaval.ca>

mgamma <- function(order, shape, rate = 1, scale = 1/rate)
    .External(C_actuar_do_dpq, "mgamma", order, shape, scale, FALSE)

levgamma <- function(limit, shape, rate = 1, scale = 1/rate, order = 1)
    .External(C_actuar_do_dpq, "levgamma", limit, shape, scale, order, FALSE)

mgfgamma <- function(t, shape, rate = 1, scale = 1/rate, log = FALSE)
    .External(C_actuar_do_dpq, "mgfgamma", t, shape, scale, log)