zad.est: MLE of the zero adjusted Dirichlet distribution

In Compositional: Compositional Data Analysis

MLE of the zero adjusted Dirichlet distribution

Description

MLE of the zero adjusted Dirichlet distribution.

Usage

zad.est(y)

Arguments

y	A matrix with the compositional data.

Details

A zero adjusted Dirichlet distribution is being fitted and its parameters are estimated.

Value

A list including:

loglik	The value of the log-likelihood.
phi	The precision parameter. If covariates are linked with it (function "diri.reg2"), this will be a vector.
mu	The mean vector of the distribution.
runtime	The time required by the model..

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris [e-mail].

References

Tsagris M. and Stewart C. (2018). A Dirichlet regression model for compositional data with zeros. Lobachevskii Journal of Mathematics, 39(3): 398–412.

Preprint available from https://arxiv.org/pdf/1410.5011.pdf

See Also

zadr, diri.nr, zilogitnorm.est, zeroreplace

Examples

y <- as.matrix(iris[, 1:3])
y <- y / rowSums(y)
mod1 <- diri.nr(y)
y[sample(1:450, 15) ] <- 0
mod2 <- zad.est(y)

Compositional documentation built on Oct. 9, 2024, 5:10 p.m.