Identity covariance structure

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

Usage

ism(x)

Arguments

x

Factor, character vector, numeric design, or matrix defining covariance levels.

Details

ism returns \(K=I\). It has no covariance-shape parameters; the only unknown covariance scale is the \(\sigma^2\) supplied by vsm. It is commonly used as the final term of vsm to indicate an independent main effect.

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(ism(id))
vsm(dsm(environment), ism(genotype))
} # }