% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/xgb.ggplot.R, R/xgb.plot.deepness.R
\name{xgb.ggplot.deepness}
\alias{xgb.ggplot.deepness}
\alias{xgb.plot.deepness}
\title{Plot model trees deepness}
\usage{
xgb.ggplot.deepness(model = NULL, which = c("2x1", "max.depth", "med.depth",
  "med.weight"))

xgb.plot.deepness(model = NULL, which = c("2x1", "max.depth", "med.depth",
  "med.weight"), plot = TRUE, ...)
}
\arguments{
\item{model}{either an \code{xgb.Booster} model generated by the \code{xgb.train} function
or a data.table result of the \code{xgb.model.dt.tree} function.}

\item{which}{which distribution to plot (see details).}

\item{plot}{(base R barplot) whether a barplot should be produced. 
If FALSE, only a data.table is returned.}

\item{...}{other parameters passed to \code{barplot} or \code{plot}.}
}
\value{
Other than producing plots (when \code{plot=TRUE}), the \code{xgb.plot.deepness} function
silently returns a processed data.table where each row corresponds to a terminal leaf in a tree model,
and contains information about leaf's depth, cover, and weight (which is used in calculating predictions).

The \code{xgb.ggplot.deepness} silently returns either a list of two ggplot graphs when \code{which="2x1"}
or a single ggplot graph for the other \code{which} options.
}
\description{
Visualizes distributions related to depth of tree leafs.
\code{xgb.plot.deepness} uses base R graphics, while \code{xgb.ggplot.deepness} uses the ggplot backend.
}
\details{
When \code{which="2x1"}, two distributions with respect to the leaf depth
are plotted on top of each other:
\itemize{
 \item the distribution of the number of leafs in a tree model at a certain depth;
 \item the distribution of average weighted number of observations ("cover") 
       ending up in leafs at certain depth.
}
Those could be helpful in determining sensible ranges of the \code{max_depth} 
and \code{min_child_weight} parameters.

When \code{which="max.depth"} or \code{which="med.depth"}, plots of either maximum or median depth
per tree with respect to tree number are created. And \code{which="med.weight"} allows to see how
a tree's median absolute leaf weight changes through the iterations.

This function was inspired by the blog post
\url{http://aysent.github.io/2015/11/08/random-forest-leaf-visualization.html}.
}
\examples{

data(agaricus.train, package='xgboost')

# Change max_depth to a higher number to get a more significant result
bst <- xgboost(data = agaricus.train$data, label = agaricus.train$label, max_depth = 6,
               eta = 0.1, nthread = 2, nrounds = 50, objective = "binary:logistic",
               subsample = 0.5, min_child_weight = 2)

xgb.plot.deepness(bst)
xgb.ggplot.deepness(bst)

xgb.plot.deepness(bst, which='max.depth', pch=16, col=rgb(0,0,1,0.3), cex=2)

xgb.plot.deepness(bst, which='med.weight', pch=16, col=rgb(0,0,1,0.3), cex=2)

}
\seealso{
\code{\link{xgb.train}}, \code{\link{xgb.model.dt.tree}}.
}
