86 lines
2.6 KiB
C++
86 lines
2.6 KiB
C++
/*!
|
|
* Copyright 2018-2019 by Contributors
|
|
*/
|
|
#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 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(kCols)));
|
|
cfg.emplace_back(std::pair<std::string, std::string>(
|
|
"min_split_loss", "10"));
|
|
|
|
// 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} };
|
|
std::shared_ptr<DMatrix> p_dmat {
|
|
RandomDataGenerator{32, 10, 0}.GenerateDMatrix() };
|
|
|
|
auto lparam = CreateEmptyGenericParam(GPUIDX);
|
|
|
|
// prepare tree
|
|
RegTree tree = RegTree();
|
|
tree.param.UpdateAllowUnknown(cfg);
|
|
std::vector<RegTree*> trees {&tree};
|
|
// prepare pruner
|
|
std::unique_ptr<TreeUpdater> pruner(TreeUpdater::Create("prune", &lparam));
|
|
pruner->Configure(cfg);
|
|
|
|
// loss_chg < min_split_loss;
|
|
tree.ExpandNode(0, 0, 0, true, 0.0f, 0.3f, 0.4f, 0.0f, 0.0f);
|
|
pruner->Update(&gpair, p_dmat.get(), trees);
|
|
|
|
ASSERT_EQ(tree.NumExtraNodes(), 0);
|
|
|
|
// loss_chg > min_split_loss;
|
|
tree.ExpandNode(0, 0, 0, true, 0.0f, 0.3f, 0.4f, 11.0f, 0.0f);
|
|
pruner->Update(&gpair, p_dmat.get(), trees);
|
|
|
|
ASSERT_EQ(tree.NumExtraNodes(), 2);
|
|
|
|
// loss_chg == min_split_loss;
|
|
tree.Stat(0).loss_chg = 10;
|
|
pruner->Update(&gpair, p_dmat.get(), trees);
|
|
|
|
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, p_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, p_dmat.get(), trees);
|
|
ASSERT_EQ(tree.NumExtraNodes(), 2);
|
|
}
|
|
} // namespace tree
|
|
} // namespace xgboost
|