mt_build_sigma: Build variance-covariance matrix
In wbonat/mglm4twin: Multivariate Generalized linear Models for Twin Data

mt_build_sigma

R Documentation

Build variance-covariance matrix

This function builds a variance-covariance matrix, based on the variance function and Omega matrix.

mt_build_sigma(
  mu,
  tau,
  power,
  Z,
  Ntrial,
  variance,
  power_fixed,
  inverse = FALSE,
  compute_derivative_beta = TRUE
)

`mu`	List with expected values and derivatives. In general the output from `mt_link_function`.
`tau`	A numeric vector.
`power`	A list of numeric or numeric vector. It should be one number for all variance functions except binomialPQ, in that case the argument specifies both p and q. Each slot of the list should specify the power parameter for each response variable.
`Z`	A list of matrices.
`Ntrial`	Number of trials for binomial data.
`variance`	String specifing the variance function: constant, tweedie, poisson_tweedie, binomialP or binomialPQ.
`power_fixed`	Logical if the power parameter is fixed at initial value (TRUE). In the case power_fixed = FALSE the power parameter will be estimated.
`compute_derivative_beta`	Logical. Compute or not the derivative with respect to regression parameters.

A list with \Sigma, \Sigma^{-1} and the derivative of \Sigma with respect to the power, tau and beta parameters.

Wagner Hugo Bonat, wbonat@ufpr.br