at creates a diagonal covariance structure for specific levels of the random effect.
Usage
at(x, levs)
Arguments
x
vector of observations for the random effect.
levs
levels of the random effect to use for building the incidence matrices.
Value
$res
a list with the provided vector and the variance covariance structure expected.
References
Covarrubias-Pazaran G (2016) Genome assisted prediction of quantitative traits using the R package sommer. PLoS ONE 11(6): doi:10.1371/journal.pone.0156744
See Also
The function vs to know how to use at in the mmer solver.