Merge pull request #198 from pommedeterresautee/master

Add new nrow function for xgb.DMatrix + small function doc changes

R-package/R/getinfo.xgb.DMatrix.R

@@ -4,6 +4,15 @@ setClass('xgb.DMatrix')
 #' 
 #' Get information of an xgb.DMatrix object
 #' 
+#' The information can be one of the following:
+#' 
+#' \itemize{
+#'     \item \code{label}: label Xgboost learn from ;
+#'     \item \code{weight}: to do a weight rescale ;
+#'     \item \code{base_margin}: base margin is the base prediction Xgboost will boost from ;
+#'     \item \code{nrow}: number of rows of the \code{xgb.DMatrix}.
+#' }
+#' 
 #' @examples
 #' data(agaricus.train, package='xgboost')
 #' train <- agaricus.train
@@ -19,7 +28,9 @@ getinfo <- function(object, ...){
     UseMethod("getinfo")
 }
 
-#' @param object Object of class "xgb.DMatrix"
+
+
+#' @param object Object of class \code{xgb.DMatrix}
 #' @param name the name of the field to get
 #' @param ... other parameters
 #' @rdname getinfo

R-package/R/nrow.xgb.DMatrix.R

@@ -0,0 +1,19 @@
+setGeneric("nrow")
+
+#' @title Number of xgb.DMatrix rows
+#' @description \code{nrow} return the number of rows present in the \code{xgb.DMatrix}.
+#' @param x Object of class \code{xgb.DMatrix}
+#' 
+#' @examples
+#' data(agaricus.train, package='xgboost')
+#' train <- agaricus.train
+#' dtrain <- xgb.DMatrix(train$data, label=train$label)
+#' stopifnot(nrow(dtrain) == nrow(train$data))
+#' 
+#' @export
+setMethod("nrow",
+          signature = "xgb.DMatrix",
+          definition = function(x) {
+            xgb.numrow(x)
+          }
+)

R-package/R/setinfo.xgb.DMatrix.R

@@ -2,6 +2,15 @@
 #' 
 #' Set information of an xgb.DMatrix object
 #' 
+#' It can be one of the following:
+#' 
+#' \itemize{
+#'     \item \code{label}: label Xgboost learn from ;
+#'     \item \code{weight}: to do a weight rescale ;
+#'     \item \code{base_margin}: base margin is the base prediction Xgboost will boost from ;
+#'     \item \code{group}.
+#' }
+#' 
 #' @examples
 #' data(agaricus.train, package='xgboost')
 #' train <- agaricus.train

R-package/R/xgboost.R

@@ -45,7 +45,7 @@
 #' train <- agaricus.train
 #' test <- agaricus.test
 #' bst <- xgboost(data = train$data, label = train$label, max.depth = 2, 
-#'                eta = 1, nthread = 2, nround = 2,objective = "binary:logistic")
+#'                eta = 1, nthread = 2, nround = 2, objective = "binary:logistic")
 #' pred <- predict(bst, test$data)
 #' 
 #' @export