| Generalised Dirichlet random values simulation {Compositional} | R Documentation |
Generalised Dirichlet random values simulation
Description
Generalised Dirichlet random values simulation.
Usage
rgendiri(n, a, b)
Arguments
n |
The sample size, a numerical value. |
a |
A numerical vector with the shape parameter values of the Gamma distribution. |
b |
A numerical vector with the scale parameter values of the Gamma distribution. |
Details
The algorithm is straightforward, for each vector, independent gamma values are generated and
then divided by their total sum. The difference with rdiri is that
here the Gamma distributed variables are not equally scaled.
Value
A matrix with the simulated data.
Author(s)
Michail Tsagris.
R implementation and documentation: Michail Tsagris mtsagris@uoc.gr.
References
Ng Kai Wang, Guo-Liang Tian and Man-Lai Tang (2011). Dirichlet and related distributions: Theory, methods and applications. John Wiley & Sons.
Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.
See Also
rdiri, diri.est, diri.nr, diri.contour
Examples
a <- c(1, 2, 3)
b <- c(2, 3, 4)
x <- rgendiri(100, a, b)