From cfc5e4fe8b2dddc2c3794267d461246ae8cddc35 Mon Sep 17 00:00:00 2001
From: shiyu1994 <shiyu_k1994@qq.com>
Date: Thu, 2 Jul 2020 13:09:10 +0800
Subject: [PATCH] store the true split gain in tree model (#3196)

---
 src/treelearner/serial_tree_learner.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/treelearner/serial_tree_learner.cpp b/src/treelearner/serial_tree_learner.cpp
index db5cd0b4395d..97e0f91f9d9a 100644
--- a/src/treelearner/serial_tree_learner.cpp
+++ b/src/treelearner/serial_tree_learner.cpp
@@ -577,7 +577,8 @@ void SerialTreeLearner::SplitInner(Tree* tree, int best_leaf, int* left_leaf,
         static_cast<data_size_t>(best_split_info.right_count),
         static_cast<double>(best_split_info.left_sum_hessian),
         static_cast<double>(best_split_info.right_sum_hessian),
-        static_cast<float>(best_split_info.gain),
+        // store the true split gain in tree model
+        static_cast<float>(best_split_info.gain + config_->min_gain_to_split),
         train_data_->FeatureBinMapper(inner_feature_index)->missing_type(),
         best_split_info.default_left);
   } else {
@@ -613,7 +614,8 @@ void SerialTreeLearner::SplitInner(Tree* tree, int best_leaf, int* left_leaf,
         static_cast<data_size_t>(best_split_info.right_count),
         static_cast<double>(best_split_info.left_sum_hessian),
         static_cast<double>(best_split_info.right_sum_hessian),
-        static_cast<float>(best_split_info.gain),
+        // store the true split gain in tree model
+        static_cast<float>(best_split_info.gain + config_->min_gain_to_split),
         train_data_->FeatureBinMapper(inner_feature_index)->missing_type());
   }