R/randcov_initial.R
randcov_initial.Rd
Create a random effects (co)variance parameter initial object that specifies initial and/or known values to use while estimating random effect variances with modeling functions.
randcov_initial(..., known)
Arguments to randcov_params()
.
A character vector indicating which random effect variances are to be
assumed known. The value "given"
is shorthand for assuming all
random effect variances given to randcov_initial()
are assumed known.
A list with two elements: initial
and is_known
.
initial
is a named numeric vector indicating the random effect variances
with specified initial and/or known values. is_known
is a named
logical vector indicating whether the random effect variances in
initial
are known or not.
A random effect is specified as \(Zu\), where \(Z\) is the random
effects design matrix and u
is the random effect. The covariance of
\(Zu\) is \(\sigma 2 ZZ^T\), where \(\sigma 2\) is the random effect
variance, and \(Z^T\) is the transpose of \(Z\).
randcov_initial(group = 1)
#> $initial
#> group
#> 1
#>
#> $is_known
#> group
#> FALSE
#>
randcov_initial(group = 1, known = "group")
#> $initial
#> group
#> 1
#>
#> $is_known
#> group
#> TRUE
#>