Diagonal heterogeneous covariance structure

Diagonal heterogeneous covariance structure. The returned dimensionless covariance shape is intended for use inside vsm, which supplies the single overall variance scale.

Usage

dsm(x, values = NULL, fixed = NULL, theta = NULL)

Arguments

x

Variable or design defining the covariance levels.

values

Optional positive starting variances, one per level.

fixed

Logical vector of length q-1 indicating which variance-ratio parameters are fixed.

theta

Optional q by q diagonal starting covariance matrix; if supplied, its diagonal replaces values.

Details

For \(q\) levels, dsm uses the first variance as the internal scale reference and estimates \(q-1\) positive variance ratios, $$K=\mathrm{diag}(1,r_2,\ldots,r_q).$$ The ratios are optimized on log scales and reported on their natural positive scale.

Value

A list containing the incidence/design matrix in Z and a compiled CovarianceFactor v2 descriptor in covFactor, for use inside vsm.

See also

vsm, mmes.

Examples

if (FALSE) { # \dontrun{
vsm(dsm(environment), ism(genotype))
} # }