From 5de7e12704b38d81a46471e02a791d4c586a7286 Mon Sep 17 00:00:00 2001
From: Jiaming Yuan <jm.yuan@outlook.com>
Date: Mon, 6 May 2019 21:35:35 +0800
Subject: [PATCH] Change obj name to `reg:squarederror` in learner. (#4427)

* Change memory dump size in R test.
---
 R-package/tests/testthat/test_custom_objective.R | 6 +++---
 src/learner.cc                                   | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/R-package/tests/testthat/test_custom_objective.R b/R-package/tests/testthat/test_custom_objective.R
index ba0595c95..79d8eccf8 100644
--- a/R-package/tests/testthat/test_custom_objective.R
+++ b/R-package/tests/testthat/test_custom_objective.R
@@ -31,7 +31,7 @@ num_round <- 2
 test_that("custom objective works", {
   bst <- xgb.train(param, dtrain, num_round, watchlist)
   expect_equal(class(bst), "xgb.Booster")
-  expect_equal(length(bst$raw), 1094)
+  expect_equal(length(bst$raw), 1100)
   expect_false(is.null(bst$evaluation_log))
   expect_false(is.null(bst$evaluation_log$eval_error))
   expect_lt(bst$evaluation_log[num_round, eval_error], 0.03)
@@ -45,7 +45,7 @@ test_that("custom objective in CV works", {
 })
 
 test_that("custom objective using DMatrix attr works", {
-  
+
   attr(dtrain, 'label') <- getinfo(dtrain, 'label')
 
   logregobjattr <- function(preds, dtrain) {
@@ -58,5 +58,5 @@ test_that("custom objective using DMatrix attr works", {
   param$objective = logregobjattr
   bst <- xgb.train(param, dtrain, num_round, watchlist)
   expect_equal(class(bst), "xgb.Booster")
-  expect_equal(length(bst$raw), 1094)
+  expect_equal(length(bst$raw), 1100)
 })
diff --git a/src/learner.cc b/src/learner.cc
index d21f07147..b7b9f0737 100644
--- a/src/learner.cc
+++ b/src/learner.cc
@@ -171,7 +171,7 @@ class LearnerImpl : public Learner {
   explicit LearnerImpl(std::vector<std::shared_ptr<DMatrix> >  cache)
       : cache_(std::move(cache)) {
     // boosted tree
-    name_obj_ = "reg:linear";
+    name_obj_ = "reg:squarederror";
     name_gbm_ = "gbtree";
   }
 
@@ -281,7 +281,7 @@ class LearnerImpl : public Learner {
     }
 
     if (cfg_.count("objective") == 0) {
-      cfg_["objective"] = "reg:linear";
+      cfg_["objective"] = "reg:squarederror";
     }
     if (cfg_.count("booster") == 0) {
       cfg_["booster"] = "gbtree";