% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/predict-cl.R
\name{.hzr_free_vcov}
\alias{.hzr_free_vcov}
\title{Free-parameter vcov submatrix for the delta-method sandwich}
\usage{
.hzr_free_vcov(vcov_mat, p)
}
\arguments{
\item{vcov_mat}{The fitted vcov (or NULL / wrong shape).}

\item{p}{Length of the parameter vector.}
}
\value{
\code{list(vcov_use, free_idx)}, or \code{NULL} if unusable.
}
\description{
Fixed parameters (e.g. \code{fixed = "shapes"}) leave NA rows/cols in the expanded
vcov. Treat them as known-with-zero-variance: restrict the sandwich to the
free submatrix. (The CoE-conserved \code{log_mu} normally participates -- CoE fits
use the full-information vcov -- but it leaves an NA row, like a fixed
parameter, when that recomputation was unavailable.) Returns \code{NULL} (with a
warning) when CLs cannot be computed. Shared by the aggregate and decomposed
se.fit paths.
}
\keyword{internal}
