% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/callbacks.R
\name{cb.evaluation.log}
\alias{cb.evaluation.log}
\title{Callback closure for logging the evaluation history}
\usage{
cb.evaluation.log()
}
\description{
Callback closure for logging the evaluation history
}
\details{
This callback function appends the current iteration evaluation results \code{bst_evaluation}
available in the calling parent frame to the \code{evaluation_log} list in a calling frame.

The finalizer callback (called with \code{finalize = TURE} in the end) converts
the \code{evaluation_log} list into a final data.table.

The iteration evaluation result \code{bst_evaluation} must be a named numeric vector.

Note: in the column names of the final data.table, the dash '-' character is replaced with
the underscore '_' in order to make the column names more like regular R identifiers.

Callback function expects the following values to be set in its calling frame:
\code{evaluation_log},
\code{bst_evaluation},
\code{iteration}.
}
\seealso{
\code{\link{callbacks}}
}