xgboost/tests/cpp/common/test_hist_util.h
Jiaming Yuan 1f9a57d17b
[Breaking] Require format to be specified in input URI. (#9077)
Previously, we use `libsvm` as default when format is not specified. However, the dmlc
data parser is not particularly robust against errors, and the most common type of error
is undefined format.

Along with which, we will recommend users to use other data loader instead. We will
continue the maintenance of the parsers as it's currently used for many internal tests
including federated learning.
2023-04-28 19:45:15 +08:00

265 lines
9.3 KiB
C++

/*!
* Copyright 2019-2022 by XGBoost Contributors
*/
#pragma once
#include <gtest/gtest.h>
#include <fstream>
#include <random>
#include <string>
#include <vector>
#include "../../../src/common/hist_util.h"
#include "../../../src/data/adapter.h"
#include "../../../src/data/simple_dmatrix.h"
#include "../filesystem.h" // dmlc::TemporaryDirectory
#include "../helpers.h"
#ifdef __CUDACC__
#include <xgboost/json.h>
#include "../../../src/data/device_adapter.cuh"
#endif // __CUDACC__
// Some helper functions used to test both GPU and CPU algorithms
//
namespace xgboost {
namespace common {
// Generate columns with different ranges
inline std::vector<float> GenerateRandom(int num_rows, int num_columns) {
std::vector<float> x(num_rows*num_columns);
std::mt19937 rng(0);
std::uniform_real_distribution<float> dist(0.0, 1.0);
std::generate(x.begin(), x.end(), [&]() { return dist(rng); });
for (auto i = 0; i < num_columns; i++) {
for (auto j = 0; j < num_rows; j++) {
x[j * num_columns + i] += i;
}
}
return x;
}
inline std::vector<float> GenerateRandomWeights(int num_rows) {
std::vector<float> w(num_rows);
std::mt19937 rng(1);
std::uniform_real_distribution<float> dist(0.0, 1.0);
std::generate(w.begin(), w.end(), [&]() { return dist(rng); });
return w;
}
#ifdef __CUDACC__
inline data::CupyAdapter AdapterFromData(const thrust::device_vector<float> &x,
int num_rows, int num_columns) {
Json array_interface{Object()};
std::vector<Json> shape = {Json(static_cast<Integer::Int>(num_rows)),
Json(static_cast<Integer::Int>(num_columns))};
array_interface["shape"] = Array(shape);
std::vector<Json> j_data{
Json(Integer(reinterpret_cast<Integer::Int>(x.data().get()))),
Json(Boolean(false))};
array_interface["data"] = j_data;
array_interface["version"] = 3;
array_interface["typestr"] = String("<f4");
std::string str;
Json::Dump(array_interface, &str);
return data::CupyAdapter(str);
}
#endif
inline std::shared_ptr<data::SimpleDMatrix>
GetDMatrixFromData(const std::vector<float> &x, int num_rows, int num_columns) {
data::DenseAdapter adapter(x.data(), num_rows, num_columns);
return std::shared_ptr<data::SimpleDMatrix>(new data::SimpleDMatrix(
&adapter, std::numeric_limits<float>::quiet_NaN(), 1));
}
inline std::shared_ptr<DMatrix> GetExternalMemoryDMatrixFromData(
const std::vector<float>& x, int num_rows, int num_columns,
const dmlc::TemporaryDirectory& tempdir) {
// Create the svm file in a temp dir
const std::string tmp_file = tempdir.path + "/temp.libsvm";
std::ofstream fo(tmp_file.c_str());
for (auto i = 0; i < num_rows; i++) {
std::stringstream row_data;
for (auto j = 0; j < num_columns; j++) {
row_data << 1 << " " << j << ":" << std::setprecision(15)
<< x[i * num_columns + j];
}
fo << row_data.str() << "\n";
}
fo.close();
return std::shared_ptr<DMatrix>(
DMatrix::Load(tmp_file + "?format=libsvm" + "#" + tmp_file + ".cache"));
}
// Test that elements are approximately equally distributed among bins
inline void TestBinDistribution(const HistogramCuts& cuts, int column_idx,
const std::vector<float>& sorted_column,
const std::vector<float>& sorted_weights) {
std::map<int, int> bin_weights;
for (auto i = 0ull; i < sorted_column.size(); i++) {
auto bin_idx = cuts.SearchBin(sorted_column[i], column_idx);
if (bin_weights.find(bin_idx) == bin_weights.cend()) {
bin_weights[bin_idx] = 0;
}
bin_weights.at(bin_idx) += sorted_weights[i];
}
int local_num_bins = cuts.Ptrs()[column_idx + 1] - cuts.Ptrs()[column_idx];
auto total_weight = std::accumulate(sorted_weights.begin(), sorted_weights.end(),0);
int expected_bin_weight = total_weight / local_num_bins;
// Allow up to 30% deviation. This test is not very strict, it only ensures
// roughly equal distribution
int allowable_error = std::max(2, int(expected_bin_weight * 0.3));
// First and last bin can have smaller
for (auto& kv : bin_weights) {
ASSERT_LE(std::abs(bin_weights[kv.first] - expected_bin_weight),
allowable_error);
}
}
// Test sketch quantiles against the real quantiles Not a very strict
// test
inline void TestRank(const std::vector<float> &column_cuts,
const std::vector<float> &sorted_x,
const std::vector<float> &sorted_weights) {
double eps = 0.05;
auto total_weight =
std::accumulate(sorted_weights.begin(), sorted_weights.end(), 0.0);
// Ignore the last cut, its special
double sum_weight = 0.0;
size_t j = 0;
for (size_t i = 0; i < column_cuts.size() - 1; i++) {
while (column_cuts[i] > sorted_x[j]) {
sum_weight += sorted_weights[j];
j++;
}
double expected_rank = ((i + 1) * total_weight) / column_cuts.size();
double acceptable_error = std::max(2.9, total_weight * eps);
EXPECT_LE(std::abs(expected_rank - sum_weight), acceptable_error);
}
}
inline void ValidateColumn(const HistogramCuts& cuts, int column_idx,
const std::vector<float>& sorted_column,
const std::vector<float>& sorted_weights,
size_t num_bins) {
// Check the endpoints are correct
CHECK_GT(sorted_column.size(), 0);
EXPECT_LT(cuts.MinValues().at(column_idx), sorted_column.front());
EXPECT_GT(cuts.Values()[cuts.Ptrs()[column_idx]], sorted_column.front());
EXPECT_GE(cuts.Values()[cuts.Ptrs()[column_idx+1]-1], sorted_column.back());
// Check the cuts are sorted
auto cuts_begin = cuts.Values().begin() + cuts.Ptrs()[column_idx];
auto cuts_end = cuts.Values().begin() + cuts.Ptrs()[column_idx + 1];
EXPECT_TRUE(std::is_sorted(cuts_begin, cuts_end));
// Check all cut points are unique
EXPECT_EQ(std::set<float>(cuts_begin, cuts_end).size(),
static_cast<size_t>(cuts_end - cuts_begin));
auto unique = std::set<float>(sorted_column.begin(), sorted_column.end());
if (unique.size() <= num_bins) {
// Less unique values than number of bins
// Each value should get its own bin
int i = 0;
for (auto v : unique) {
ASSERT_EQ(cuts.SearchBin(v, column_idx), cuts.Ptrs()[column_idx] + i);
i++;
}
} else {
int num_cuts_column = cuts.Ptrs()[column_idx + 1] - cuts.Ptrs()[column_idx];
std::vector<float> column_cuts(num_cuts_column);
std::copy(cuts.Values().begin() + cuts.Ptrs()[column_idx],
cuts.Values().begin() + cuts.Ptrs()[column_idx + 1],
column_cuts.begin());
TestBinDistribution(cuts, column_idx, sorted_column, sorted_weights);
TestRank(column_cuts, sorted_column, sorted_weights);
}
}
inline void ValidateCuts(const HistogramCuts& cuts, DMatrix* dmat, int num_bins) {
// Collect data into columns
std::vector<std::vector<float>> columns(dmat->Info().num_col_);
for (auto& batch : dmat->GetBatches<SparsePage>()) {
auto page = batch.GetView();
ASSERT_GT(batch.Size(), 0ul);
for (auto i = 0ull; i < batch.Size(); i++) {
for (auto e : page[i]) {
columns[e.index].push_back(e.fvalue);
}
}
}
// construct weights.
std::vector<float> w = dmat->Info().group_ptr_.empty() ? dmat->Info().weights_.HostVector()
: detail::UnrollGroupWeights(dmat->Info());
// Sort
for (auto i = 0ull; i < columns.size(); i++) {
auto& col = columns.at(i);
std::vector<size_t> index(col.size());
std::iota(index.begin(), index.end(), 0);
std::sort(index.begin(), index.end(), [=](size_t a, size_t b) { return col[a] < col[b]; });
std::vector<float> sorted_column(col.size());
std::vector<float> sorted_weights(col.size(), 1.0);
const auto& w = dmat->Info().weights_.HostVector();
for (auto j = 0ull; j < col.size(); j++) {
sorted_column[j] = col[index[j]];
if (w.size() == col.size()) {
sorted_weights[j] = w[index[j]];
}
}
ValidateColumn(cuts, i, sorted_column, sorted_weights, num_bins);
}
}
/**
* \brief Test for sketching on categorical data.
*
* \param sketch Sketch function, can be on device or on host.
*/
template <typename Fn>
void TestCategoricalSketch(size_t n, size_t num_categories, int32_t num_bins,
bool weighted, Fn sketch) {
auto x = GenerateRandomCategoricalSingleColumn(n, num_categories);
auto dmat = GetDMatrixFromData(x, n, 1);
dmat->Info().feature_types.HostVector().push_back(FeatureType::kCategorical);
if (weighted) {
std::vector<float> weights(n, 0);
SimpleLCG lcg;
SimpleRealUniformDistribution<float> dist(0, 1);
for (auto& v : weights) {
v = dist(&lcg);
}
dmat->Info().weights_.HostVector() = weights;
}
ASSERT_EQ(dmat->Info().feature_types.Size(), 1);
auto cuts = sketch(dmat.get(), num_bins);
ASSERT_EQ(cuts.MaxCategory(), num_categories - 1);
std::sort(x.begin(), x.end());
auto n_uniques = std::unique(x.begin(), x.end()) - x.begin();
ASSERT_NE(n_uniques, x.size());
ASSERT_EQ(cuts.TotalBins(), n_uniques);
ASSERT_EQ(n_uniques, num_categories);
auto& values = cuts.cut_values_.HostVector();
ASSERT_TRUE(std::is_sorted(values.cbegin(), values.cend()));
auto is_unique = (std::unique(values.begin(), values.end()) - values.begin()) == n_uniques;
ASSERT_TRUE(is_unique);
x.resize(n_uniques);
for (decltype(n_uniques) i = 0; i < n_uniques; ++i) {
ASSERT_EQ(x[i], values[i]);
}
}
} // namespace common
} // namespace xgboost