gamma_par_from_gen_gamma_par: Gamma parameters from generalized gamma parameters and...
In niknap/ScalingFunctions: Collection of functions for scaling of distributions

Description Usage Arguments Value Author(s)

View source: R/gamma_par_from_gen_gamma_par_function.R

If a variable x follows a gamma distribution the dependent variable y, which is related to x via a power law relationship y=a*x^b follows a generalized gamma distribution (GG). The parameters of the gamma distribution can be calculated from the input GG parameters and the power law coefficients. Two alternative formulations for the GG exist in the literature, one of which uses parameters named a, d, p while the other one uses mu, sigma, Q (e.g., R package flexsurv). Both parameter sets are accepted by this function. For parameter conversion see also: https://en.wikipedia.org/wiki/Generalized_gamma_distribution

gamma_par_from_gen_gamma_par(
  pl.fac,
  pl.exp,
  gg.a,
  gg.d,
  gg.p,
  gg.mu,
  gg.sigma,
  gg.Q,
  flexsurv.form = F
)

`pl.fac`	Power law prefactor
`pl.exp`	Power law exponent
`gg.a`	GG parameter
`gg.d`	GG parameter
`gg.p`	GG parameter
`gg.mu`	GG parameter (flexsurv form)
`gg.sigma`	GG parameter (flexsurv form)
`gg.Q`	GG parameter (flexsurv form)
`flexsurv.form`	Switch whether to use the default GG parameter set (a, d, p) or the flexsurv GG parameter set (mu, sigma, Q)