xgboost/R-package/R/xgb.dump.R
Vadim Khotilovich b21e658a02 [R-package] JSON dump format and a couple of bugfixes (#1855)
* [R-package] JSON tree dump interface

* [R-package] precision bugfix in xgb.attributes

* [R-package] bugfix for cb.early.stop called from xgb.cv

* [R-package] a bit more clarity on labels checking in xgb.cv

* [R-package] test JSON dump for gblinear as well

* whitespace lint
2016-12-11 19:48:39 +01:00

69 lines
2.9 KiB
R

#' Save xgboost model to text file
#'
#' Save a xgboost model to text file. Could be parsed later.
#'
#' @param model the model object.
#' @param fname the name of the text file where to save the model text dump. If not provided or set to \code{NULL} the function will return the model as a \code{character} vector.
#' @param fmap feature map file representing the type of feature.
#' Detailed description could be found at
#' \url{https://github.com/dmlc/xgboost/wiki/Binary-Classification#dump-model}.
#' See demo/ for walkthrough example in R, and
#' \url{https://github.com/dmlc/xgboost/blob/master/demo/data/featmap.txt}
#' for example Format.
#' @param with_stats whether dump statistics of splits
#' When this option is on, the model dump comes with two additional statistics:
#' gain is the approximate loss function gain we get in each split;
#' cover is the sum of second order gradient in each node.
#' @param dump_fomat either 'text' or 'json' format could be specified.
#' @param ... currently not used
#'
#' @return
#' if fname is not provided or set to \code{NULL} the function will return the model as a \code{character} vector. Otherwise it will return \code{TRUE}.
#'
#' @examples
#' data(agaricus.train, package='xgboost')
#' data(agaricus.test, package='xgboost')
#' train <- agaricus.train
#' test <- agaricus.test
#' bst <- xgboost(data = train$data, label = train$label, max_depth = 2,
#' eta = 1, nthread = 2, nrounds = 2, objective = "binary:logistic")
#' # save the model in file 'xgb.model.dump'
#' xgb.dump(bst, 'xgb.model.dump', with_stats = TRUE)
#'
#' # print the model without saving it to a file
#' print(xgb.dump(bst, with_stats = TRUE))
#'
#' # print in JSON format:
#' cat(xgb.dump(bst, with_stats = TRUE, dump_format='json'))
#'
#' @export
xgb.dump <- function(model = NULL, fname = NULL, fmap = "", with_stats=FALSE, dump_format = c("text", "json"), ...) {
check.deprecation(...)
dump_format <- match.arg(dump_format)
if (class(model) != "xgb.Booster")
stop("model: argument must be of type xgb.Booster")
if (!(class(fname) %in% c("character", "NULL") && length(fname) <= 1))
stop("fname: argument must be of type character (when provided)")
if (!(class(fmap) %in% c("character", "NULL") && length(fmap) <= 1))
stop("fmap: argument must be of type character (when provided)")
model <- xgb.Booster.check(model)
model_dump <- .Call("XGBoosterDumpModel_R", model$handle, fmap, as.integer(with_stats),
as.character(dump_format), PACKAGE = "xgboost")
if (is.null(fname))
model_dump <- stri_replace_all_regex(model_dump, '\t', '')
if (dump_format == "text")
model_dump <- unlist(stri_split_regex(model_dump, '\n'))
model_dump <- grep('^\\s*$', model_dump, invert = TRUE, value = TRUE)
if (is.null(fname)) {
return(model_dump)
} else {
writeLines(model_dump, fname)
return(TRUE)
}
}