% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/long-grmtree-latentpar.R
\name{latentpar_longitudinal_grmtree}
\alias{latentpar_longitudinal_grmtree}
\title{Extract Latent Trait Parameters from Longitudinal GRM Tree}
\usage{
latentpar_longitudinal_grmtree(object, node = NULL, ...)
}
\arguments{
\item{object}{A \code{longitudinal_grmtree} object.}

\item{node}{Optional vector of node IDs. If NULL, all terminal nodes.}

\item{...}{Additional arguments (currently unused).}
}
\value{
A data.frame with columns:
\describe{
\item{Node}{Terminal node ID}
\item{n}{Sample size in the node}
\item{mu_T2}{Latent mean at T2 (positive = improvement)}
\item{sigma2_T2}{Latent variance at T2}
\item{cor_T1_T2}{Correlation between T1 and T2 latent traits}
}
}
\description{
Extracts the latent trait distribution parameters from each terminal node of
a longitudinal GRM tree: the T2 latent mean shift (\eqn{\mu_{T2}}), the T2
latent variance (\eqn{\sigma^2_{T2}}), and the T1-T2 correlation.
}
\examples{
\dontshow{if (interactive()) withAutoprint(\{ # examplesIf}
library(grmtree)

# Load the synthetic longitudinal data
data("grmtree_long_data", package = "grmtree")

  # Prepare the wide-format response matrix
  items_t1 <- c("MOS_Listen", "MOS_Info", "MOS_Advice_Crisis", "MOS_Confide",
                "MOS_Advice_Want", "MOS_Fears", "MOS_Personal", "MOS_Understand")
  ld <- prepare_longitudinal_data(
    data = grmtree_long_data,
    items_t1 = items_t1,
    items_t2 = paste0(items_t1, "_year1"),
    covariates = c("sex", "age", "residency", "job",
                   "education", "comorbidity_count", "ever_smoker")
  )

  # Phase 1: fit the longitudinal GRM tree
  ltree <- longitudinal_grmtree(
    resp_wide ~ sex + age + residency + job +
      education + comorbidity_count + ever_smoker,
    data = ld, n_items = 8,
    control = grmtree.control(minbucket = 200)
  )

  # Print latent trait summary
  latent <- latentpar_longitudinal_grmtree(ltree)
  print(latent)
\dontshow{\}) # examplesIf}
}
\seealso{
\code{\link{longitudinal_grmtree}} for Phase 1 (tree fitting),
\code{\link{fscores_longitudinal_grmtree}}, for computing factor scores for
longitudinal GRMTree
}
