% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/Persistence.R
\name{boundary_info}
\alias{boundary_info}
\title{Get the boundary matrix and its reduction information in matrix form}
\usage{
boundary_info(filist, max_dimension = NULL)
}
\arguments{
\item{filist}{Filtration list, each element includes simplex and time.}

\item{max_dimension}{Optional maximum homology dimension to eventually
report via \code{\link{extract_persistence_pairs}}. When set,
\code{filist} is first restricted to \code{max_dimension + 1} (one
extra dimension, kept only so dimension-\code{max_dimension} classes
are correctly killed - see \code{\link{restrict_filtration}}'s
Details) before the boundary matrix is built and reduced. Leave
\code{NULL} (default) to fall back to \code{filist}'s own
\code{"max_dimension"} attribute (set automatically when it came from
\code{\link{build_filtration}} with \code{max_dimension} supplied
there), or to use \code{filist} uncapped if that attribute is also
absent.}
}
\value{
A list containing the boundary matrix, the last boundary row, the
  pivot owner for persistence extraction, and \code{filist} - the exact
  (possibly \code{max_dimension}-restricted) filtration list the other
  three elements were computed from, re-tagged with the same
  \code{"max_dimension"} attribute so \code{\link{extract_persistence_pairs}}
  can auto-detect it too. Always pass THIS \code{filist} back into
  \code{\link{extract_persistence_pairs}}, not your original one - see its
  Details for why.
}
\description{
Get the boundary matrix and its reduction information in matrix form
}
\examples{
points <- matrix(c(0, 1, 1, 0, 0, 0, 1, 1), ncol = 2)
filtration <- build_filtration(points, method = "VR", eps_max = 1.2)
res <- boundary_info(filtration)
}
