style cleanup, incomplete CV

R-package/R/xgb.train.R

@@ -16,7 +16,7 @@
 #'
 #'   See \url{https://github.com/tqchen/xgboost/wiki/Parameters} for 
 #'   further details. See also inst/examples/demo.R for walkthrough example in R.
-#' @param dtrain takes an \code{xgb.DMatrix} as the input.
+#' @param data takes an \code{xgb.DMatrix} as the input.
 #' @param nrounds the max number of iterations
 #' @param watchlist what information should be printed when \code{verbose=1} or
 #'   \code{verbose=2}. Watchlist is used to specify validation set monitoring
@@ -64,8 +64,9 @@
 #' bst <- xgb.train(param, dtrain, nround = 2, watchlist, logregobj, evalerror)
 #' @export
 #' 
-xgb.train <- function(params=list(), dtrain, nrounds, watchlist = list(), 
+xgb.train <- function(params=list(), data, nrounds, watchlist = list(), 
                       obj = NULL, feval = NULL, ...) {
+  dtrain <- data
   if (typeof(params) != "list") {
     stop("xgb.train: first argument params must be list")
   }
@@ -75,37 +76,10 @@ xgb.train <- function(params=list(), dtrain, nrounds, watchlist = list(),
   params = append(params, list(...))
   bst <- xgb.Booster(params, append(watchlist, dtrain))
   for (i in 1:nrounds) {
-    if (is.null(obj)) {
-      succ <- xgb.iter.update(bst, dtrain, i - 1)
-    } else {
-      pred <- xgb.predict(bst, dtrain)
-      gpair <- obj(pred, dtrain)
-      succ <- xgb.iter.boost(bst, dtrain, gpair)
-    }
+    succ <- xgb.iter.update(bst, dtrain, i - 1, obj)
     if (length(watchlist) != 0) {
-      if (is.null(feval)) {
-        msg <- xgb.iter.eval(bst, watchlist, i - 1)
-        cat(msg)
-        cat("\n")
-      } else {
-        cat("[")
-        cat(i)
-        cat("]")
-        for (j in 1:length(watchlist)) {
-          w <- watchlist[j]
-          if (length(names(w)) == 0) {
-            stop("xgb.eval: name tag must be presented for every elements in watchlist")
-          }
-          ret <- feval(xgb.predict(bst, w[[1]]), w[[1]])
-          cat("\t")
-          cat(names(w))
-          cat("-")
-          cat(ret$metric)
-          cat(":")
-          cat(ret$value)
-        }
-        cat("\n")
-      }
+      msg <- xgb.iter.eval(bst, watchlist, i - 1, feval)
+      cat(paste(msg, "\n", sep=""))
     }
   }
   return(bst)