% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/gbt.R
\name{cv.gbt}
\alias{cv.gbt}
\title{Cross-validation for Gradient Boosted Trees}
\usage{
cv.gbt(
  object,
  K = 5,
  repeats = 1,
  params = list(),
  nrounds = 500,
  early_stopping_rounds = 10,
  nthread = 12,
  train = NULL,
  type = "classification",
  trace = TRUE,
  seed = 1234,
  maximize = NULL,
  fun,
  ...
)
}
\arguments{
\item{object}{Object of type "gbt" or "ranger"}

\item{K}{Number of cross validation passes to use (aka nfold)}

\item{repeats}{Repeated cross validation}

\item{params}{List of parameters (see XGBoost documentation)}

\item{nrounds}{Number of trees to create}

\item{early_stopping_rounds}{Early stopping rule}

\item{nthread}{Number of parallel threads to use. Defaults to 12 if available}

\item{train}{An optional xgb.DMatrix object containing the original training data. Not needed when using Radiant's gbt function}

\item{type}{Model type ("classification" or "regression")}

\item{trace}{Print progress}

\item{seed}{Random seed to use as the starting point}

\item{maximize}{When a custom function is used, xgb.cv requires the user indicate if the function output should be maximized (TRUE) or minimized (FALSE)}

\item{fun}{Function to use for model evaluation (i.e., auc for classification and RMSE for regression)}

\item{...}{Additional arguments to be passed to 'fun'}
}
\value{
A data.frame sorted by the mean of the performance metric
}
\description{
Cross-validation for Gradient Boosted Trees
}
\details{
See \url{https://radiant-rstats.github.io/docs/model/gbt.html} for an example in Radiant
}
\examples{
\dontrun{
result <- gbt(dvd, "buy", c("coupon", "purch", "last"))
cv.gbt(result, params = list(max_depth = 1:6))
cv.gbt(result, params = list(max_depth = 1:6), fun = "logloss")
cv.gbt(
  result,
  params = list(learning_rate = seq(0.1, 1.0, 0.1)),
  maximize = TRUE, fun = profit, cost = 1, margin = 5
)
result <- gbt(diamonds, "price", c("carat", "color", "clarity"), type = "regression")
cv.gbt(result, params = list(max_depth = 1:2, min_child_weight = 1:2))
cv.gbt(result, params = list(learning_rate = seq(0.1, 0.5, 0.1)), fun = Rsq, maximize = TRUE)
cv.gbt(result, params = list(learning_rate = seq(0.1, 0.5, 0.1)), fun = MAE, maximize = FALSE)
}

}
\seealso{
\code{\link{gbt}} to generate an initial model that can be passed to cv.gbt

\code{\link{Rsq}} to calculate an R-squared measure for a regression

\code{\link{RMSE}} to calculate the Root Mean Squared Error for a regression

\code{\link{MAE}} to calculate the Mean Absolute Error for a regression

\code{\link{auc}} to calculate the area under the ROC curve for classification

\code{\link{profit}} to calculate profits for classification at a cost/margin threshold
}