Validate generative-model parameters \(\theta\)

Checks that true_theta stores the DeCovarT mixture parameters:

• p: mixing proportions of length \(J\), or a matrix \(J\times N\) of sample-wise proportions (each column on the simplex);

• mu: mean signature \(\boldsymbol{\mu}\in\mathcal{M}_{G\times J}\) (also accepts \(J\times G\));

• sigma and/or Theta: array \(G\times G\times J\) of covariances and/or precision matrices.

Usage

check_true_theta(
  true_theta,
  require_p = TRUE,
  J = NULL,
  second_moment = c("either", "sigma", "Theta")
)

Arguments

true_theta

Named list with the fields above.

require_p

Logical; if TRUE (default), p must be present and valid. If FALSE, a missing p is allowed (callers may default it).

J

Optional expected number of cell types. When NULL, inferred from mu / the third dimension of sigma or Theta.

second_moment

Which second-moment field to require: "sigma", "Theta", or "either" (default: at least one of sigma / Theta).

Value

TRUE invisibly if the structure is valid; otherwise stops with an informative error.

See also

compute_average_overlap(), compute_average_jeffreys()

Examples

theta <- list(
  p = c(0.5, 0.5),
  mu = cbind(c(0, 0), c(3, 0)),
  sigma = array(c(diag(2), diag(2)), dim = c(2, 2, 2))
)
check_true_theta(theta)