fix example

R-package/man/xgb.plot.importance.Rd

@@ -28,13 +28,12 @@ data(agaricus.train, package='xgboost')
 #Both dataset are list with two items, a sparse matrix and labels
 #(labels = outcome column which will be learned).
 #Each column of the sparse Matrix is a feature in one hot encoding format.
-train <- agaricus.train
 
-bst <- xgboost(data = train$data, label = train$label, max.depth = 2,
+bst <- xgboost(data = agaricus.train$data, label = agaricus.train$label, max.depth = 2,
                eta = 1, nthread = 2, nround = 2,objective = "binary:logistic")
 
-#train$data@Dimnames[[2]] represents the column names of the sparse matrix.
-importance_matrix <- xgb.importance(train$data@Dimnames[[2]], model = bst)
+#agaricus.train$data@Dimnames[[2]] represents the column names of the sparse matrix.
+importance_matrix <- xgb.importance(agaricus.train$data@Dimnames[[2]], model = bst)
 xgb.plot.importance(importance_matrix)
 
 }