add documentation notes

R-package/R/xgb.dump.R

@@ -1,11 +1,23 @@
-# dump model
-xgb.dump <- function(booster, fname, fmap = "") {
-  if (class(booster) != "xgb.Booster") {
+#' 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 binary file.
+#' @param fmap TODO(tqchen)
+#' 
+#' @examples
+#' data(iris)
+#' bst <- xgboost(as.matrix(iris[,1:4]),as.numeric(iris[,5]), nrounds = 2)
+#' xgb.dump(bst, 'iris.xgb.model.dump')
+#' 
+xgb.dump <- function(model, fname, fmap = "") {
+  if (class(model) != "xgb.Booster") {
     stop("xgb.dump: first argument must be type xgb.Booster")
   }
   if (typeof(fname) != "character") {
     stop("xgb.dump: second argument must be type character")
   }
-  .Call("XGBoosterDumpModel_R", booster, fname, fmap, PACKAGE = "xgboost")
+  .Call("XGBoosterDumpModel_R", model, fname, fmap, PACKAGE = "xgboost")
   return(TRUE)
 }