xgboost/tests/cpp/objective/test_lambdarank_obj.cc

107 lines
4.3 KiB
C++

/**
* Copyright 2023 by XGBoost Contributors
*/
#include "test_lambdarank_obj.h"
#include <gtest/gtest.h> // for Test, Message, TestPartResult, CmpHel...
#include <cstddef> // for size_t
#include <initializer_list> // for initializer_list
#include <map> // for map
#include <memory> // for unique_ptr, shared_ptr, make_shared
#include <numeric> // for iota
#include <string> // for char_traits, basic_string, string
#include <vector> // for vector
#include "../../../src/common/ranking_utils.h" // for LambdaRankParam
#include "../../../src/common/ranking_utils.h" // for NDCGCache, LambdaRankParam
#include "../helpers.h" // for CheckRankingObjFunction, CheckConfigReload
#include "xgboost/base.h" // for GradientPair, bst_group_t, Args
#include "xgboost/context.h" // for Context
#include "xgboost/data.h" // for MetaInfo, DMatrix
#include "xgboost/host_device_vector.h" // for HostDeviceVector
#include "xgboost/linalg.h" // for Tensor, All, TensorView
#include "xgboost/objective.h" // for ObjFunction
#include "xgboost/span.h" // for Span
namespace xgboost::obj {
void InitMakePairTest(Context const* ctx, MetaInfo* out_info, HostDeviceVector<float>* out_predt) {
out_predt->SetDevice(ctx->gpu_id);
MetaInfo& info = *out_info;
info.num_row_ = 128;
info.labels.ModifyInplace([&](HostDeviceVector<float>* data, common::Span<std::size_t> shape) {
shape[0] = info.num_row_;
shape[1] = 1;
auto& h_data = data->HostVector();
h_data.resize(shape[0]);
for (std::size_t i = 0; i < h_data.size(); ++i) {
h_data[i] = i % 2;
}
});
std::vector<float> predt(info.num_row_);
std::iota(predt.rbegin(), predt.rend(), 0.0f);
out_predt->HostVector() = predt;
}
TEST(LambdaRank, MakePair) {
Context ctx;
MetaInfo info;
HostDeviceVector<float> predt;
InitMakePairTest(&ctx, &info, &predt);
ltr::LambdaRankParam param;
param.UpdateAllowUnknown(Args{{"lambdarank_pair_method", "topk"}});
ASSERT_TRUE(param.HasTruncation());
std::shared_ptr<ltr::RankingCache> p_cache = std::make_shared<ltr::NDCGCache>(&ctx, info, param);
auto const& h_predt = predt.ConstHostVector();
{
auto rank_idx = p_cache->SortedIdx(&ctx, h_predt);
for (std::size_t i = 0; i < h_predt.size(); ++i) {
ASSERT_EQ(rank_idx[i], static_cast<std::size_t>(*(h_predt.crbegin() + i)));
}
std::int32_t n_pairs{0};
MakePairs(&ctx, 0, p_cache, 0, info.labels.HostView().Slice(linalg::All(), 0), rank_idx,
[&](auto i, auto j) {
ASSERT_GT(j, i);
ASSERT_LT(i, p_cache->Param().NumPair());
++n_pairs;
});
ASSERT_EQ(n_pairs, 3568);
}
auto const h_label = info.labels.HostView();
{
param.UpdateAllowUnknown(Args{{"lambdarank_pair_method", "mean"}});
auto p_cache = std::make_shared<ltr::NDCGCache>(&ctx, info, param);
ASSERT_FALSE(param.HasTruncation());
std::int32_t n_pairs = 0;
auto rank_idx = p_cache->SortedIdx(&ctx, h_predt);
MakePairs(&ctx, 0, p_cache, 0, info.labels.HostView().Slice(linalg::All(), 0), rank_idx,
[&](auto i, auto j) {
++n_pairs;
// Not in the same bucket
ASSERT_NE(h_label(rank_idx[i]), h_label(rank_idx[j]));
});
ASSERT_EQ(n_pairs, info.num_row_ * param.NumPair());
}
{
param.UpdateAllowUnknown(Args{{"lambdarank_num_pair_per_sample", "2"}});
auto p_cache = std::make_shared<ltr::NDCGCache>(&ctx, info, param);
auto rank_idx = p_cache->SortedIdx(&ctx, h_predt);
std::int32_t n_pairs = 0;
MakePairs(&ctx, 0, p_cache, 0, info.labels.HostView().Slice(linalg::All(), 0), rank_idx,
[&](auto i, auto j) {
++n_pairs;
// Not in the same bucket
ASSERT_NE(h_label(rank_idx[i]), h_label(rank_idx[j]));
});
ASSERT_EQ(param.NumPair(), 2);
ASSERT_EQ(n_pairs, info.num_row_ * param.NumPair());
}
}
} // namespace xgboost::obj