% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/ppmodel.R
\name{projection_importance}
\alias{projection_importance}
\title{Projection-coefficient variable importance.}
\usage{
projection_importance(model)
}
\arguments{
\item{model}{A \code{pptr} or \code{pprf} model.}
}
\value{
A non-negative numeric vector, one entry per feature.
}
\description{
The projection-based importance (VI2): each split's scaled absolute
projection coefficients (`|a_j| * sigma_j`) aggregated into a per-feature
score, averaged over the non-degenerate trees of a forest. Unlike
\code{\link{permuted_importance}} and \code{\link{weighted_importance}},
this measure is not OOB-based — it depends only on the fitted projector
geometry, is computed eagerly at fit time (cheap), and is available for
both single trees (\code{pptr}) and forests (\code{pprf}).
}
\details{
**Sign semantics.** Entries are non-negative by construction (absolute
coefficients scaled by each feature's standard deviation). Rely on the
ranking rather than re-normalizing.
}
\seealso{
\code{\link{permuted_importance}}, \code{\link{weighted_importance}}
}
