Hendrik/xgboost
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix pruner. (#5335)

Browse Source 
* Honor the tree depth.
* Prevent pruning pruned node.
This commit is contained in:
Jiaming Yuan
2020-02-25 08:32:46 +08:00
committed by GitHub
parent b0ed3f0a66
commit e0509b3307
5 changed files with 99 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
tests/cpp/tree/test_prune.cc
View File

@@ -1,33 +1,34 @@
/*!
* Copyright 2018-2019 by Contributors
*/
#include "../helpers.h"
#include <xgboost/data.h>
#include <xgboost/host_device_vector.h>
#include <xgboost/tree_updater.h>
#include <xgboost/learner.h>
#include <gtest/gtest.h>
#include <vector>
#include <string>
#include <memory>
#include "../helpers.h"
namespace xgboost {
namespace tree {
TEST(Updater, Prune) {
int constexpr kNCols = 16;
int constexpr kCols = 16;
std::vector<std::pair<std::string, std::string>> cfg;
cfg.emplace_back(std::pair<std::string, std::string>(
"num_feature", std::to_string(kNCols)));
cfg.emplace_back(std::pair<std::string, std::string>("num_feature",
std::to_string(kCols)));
cfg.emplace_back(std::pair<std::string, std::string>(
"min_split_loss", "10"));
cfg.emplace_back(std::pair<std::string, std::string>(
"silent", "1"));
// These data are just place holders.
HostDeviceVector<GradientPair> gpair =
{ {0.50f, 0.25f}, {0.50f, 0.25f}, {0.50f, 0.25f}, {0.50f, 0.25f},
{0.25f, 0.24f}, {0.25f, 0.24f}, {0.25f, 0.24f}, {0.25f, 0.24f} };
auto dmat = CreateDMatrix(32, 16, 0.4, 3);
auto dmat = CreateDMatrix(32, kCols, 0.4, 3);
auto lparam = CreateEmptyGenericParam(GPUIDX);
@@ -57,8 +58,29 @@ TEST(Updater, Prune) {
ASSERT_EQ(tree.NumExtraNodes(), 2);
// Test depth
// loss_chg > min_split_loss
tree.ExpandNode(tree[0].LeftChild(),
0, 0.5f, true, 0.3, 0.4, 0.5,
/*loss_chg=*/18.0f, 0.0f);
tree.ExpandNode(tree[0].RightChild(),
0, 0.5f, true, 0.3, 0.4, 0.5,
/*loss_chg=*/19.0f, 0.0f);
cfg.emplace_back(std::make_pair("max_depth", "1"));
pruner->Configure(cfg);
pruner->Update(&gpair, dmat->get(), trees);
ASSERT_EQ(tree.NumExtraNodes(), 2);
tree.ExpandNode(tree[0].LeftChild(),
0, 0.5f, true, 0.3, 0.4, 0.5,
/*loss_chg=*/18.0f, 0.0f);
cfg.emplace_back(std::make_pair("min_split_loss", "0"));
pruner->Configure(cfg);
pruner->Update(&gpair, dmat->get(), trees);
ASSERT_EQ(tree.NumExtraNodes(), 2);
delete dmat;
}
} // namespace tree
} // namespace xgboost