xgboost/R-package/man/xgb.model.dt.tree.Rd
2016-05-17 00:24:06 -05:00

55 lines
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R

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/xgb.model.dt.tree.R
\name{xgb.model.dt.tree}
\alias{xgb.model.dt.tree}
\title{Parse boosted tree model text dump}
\usage{
xgb.model.dt.tree(feature_names = NULL, model = NULL, text = NULL,
n_first_tree = NULL)
}
\arguments{
\item{feature_names}{character vector of feature names. If the model already
contains feature names, this argument should be \code{NULL} (default value)}
\item{model}{object of class \code{xgb.Booster}}
\item{text}{\code{character} vector previously generated by the \code{xgb.dump}
function (where parameter \code{with.stats = TRUE} should have been set).}
\item{n_first_tree}{limit the parsing to the \code{n} first trees.
If set to \code{NULL}, all trees of the model are parsed.}
}
\value{
A \code{data.table} with detailed information about model trees' nodes.
The columns of the \code{data.table} are:
\itemize{
\item \code{Tree}: ID of a tree in a model
\item \code{Node}: ID of a node in a tree
\item \code{ID}: unique identifier of a node in a model
\item \code{Feature}: for a branch node, it's a feature id or name (when available);
for a leaf note, it simply labels it as \code{'Leaf'}
\item \code{Split}: location of the split for a branch node (split condition is always "less than")
\item \code{Yes}: ID of the next node when the split condition is met
\item \code{No}: ID of the next node when the split condition is not met
\item \code{Missing}: ID of the next node when branch value is missing
\item \code{Quality}: either the split gain or the leaf value
\item \code{Cover}: metric related to the number of observation either seen by a split split
or collected by a leaf during training.
}
}
\description{
Parse a boosted tree model text dump into a \code{data.table} structure.
}
\examples{
data(agaricus.train, package='xgboost')
bst <- xgboost(data = agaricus.train$data, label = agaricus.train$label, max.depth = 2,
eta = 1, nthread = 2, nround = 2,objective = "binary:logistic")
xgb.model.dt.tree(colnames(agaricus.train$data), bst)
}