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Sketching from adapters (#5365)

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* Sketching from adapters

* Add weights test
This commit is contained in:
Rory Mitchell
2020-03-07 21:07:58 +13:00
committed by GitHub
parent 0dd97c206b
commit a38e7bd19c
11 changed files with 780 additions and 624 deletions
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142
tests/cpp/common/test_hist_util.h
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@@ -28,6 +28,34 @@ inline std::vector<float> GenerateRandom(int num_rows, int num_columns) {
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"] = Integer(static_cast<Integer::Int>(1));
array_interface["typestr"] = String("<f4");
std::stringstream ss;
Json::Dump(array_interface, &ss);
std::string str = ss.str();
return data::CupyAdapter(str);
}
#endif
inline std::vector<float> GenerateRandomCategoricalSingleColumn(int n,
int num_categories) {
std::vector<float> x(n);
@@ -69,21 +97,22 @@ inline std::shared_ptr<DMatrix> GetExternalMemoryDMatrixFromData(
// Test that elements are approximately equally distributed among bins
inline void TestBinDistribution(const HistogramCuts& cuts, int column_idx,
const std::vector<float>& column,
const std::vector<float>& sorted_column,const std::vector<float >&sorted_weights,
int num_bins) {
std::map<int, int> counts;
for (auto& v : column) {
counts[cuts.SearchBin(v, column_idx)]++;
std::map<int, int> bin_weights;
for (auto i = 0ull; i < sorted_column.size(); i++) {
bin_weights[cuts.SearchBin(sorted_column[i], column_idx)] += sorted_weights[i];
}
int local_num_bins = cuts.Ptrs()[column_idx + 1] - cuts.Ptrs()[column_idx];
int expected_num_elements = column.size() / local_num_bins;
// Allow about 30% deviation. This test is not very strict, it only ensures
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_num_elements * 0.3));
int allowable_error = std::max(2, int(expected_bin_weight * 0.3));
// First and last bin can have smaller
for (auto& kv : counts) {
EXPECT_LE(std::abs(counts[kv.first] - expected_num_elements),
for (auto& kv : bin_weights) {
EXPECT_LE(std::abs(bin_weights[kv.first] - expected_bin_weight),
allowable_error );
}
}
@@ -91,26 +120,29 @@ inline void TestBinDistribution(const HistogramCuts& cuts, int column_idx,
// Test sketch quantiles against the real quantiles
// Not a very strict test
inline void TestRank(const std::vector<float>& cuts,
const std::vector<float>& sorted_x) {
float eps = 0.05;
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 (auto i = 0; i < cuts.size() - 1; i++) {
int expected_rank = ((i+1) * sorted_x.size()) / cuts.size();
while (cuts[i] > sorted_x[j]) {
sum_weight += sorted_weights[j];
j++;
}
int actual_rank = j;
int acceptable_error = std::max(2, int(sorted_x.size() * eps));
ASSERT_LE(std::abs(expected_rank - actual_rank), acceptable_error);
double expected_rank = ((i + 1) * total_weight) / cuts.size();
double acceptable_error = std::max(2.0, total_weight * eps);
ASSERT_LE(std::abs(expected_rank - sum_weight), acceptable_error);
}
}
inline void ValidateColumn(const HistogramCuts& cuts, int column_idx,
const std::vector<float>& column,
const std::vector<float>& sorted_column,
const std::vector<float>& sorted_weights,
int num_bins) {
std::vector<float> sorted_column(column);
std::sort(sorted_column.begin(), sorted_column.end());
// Check the endpoints are correct
EXPECT_LT(cuts.MinValues()[column_idx], sorted_column.front());
@@ -126,40 +158,60 @@ inline void ValidateColumn(const HistogramCuts& cuts, int column_idx,
EXPECT_EQ(std::set<float>(cuts_begin, cuts_end).size(),
cuts_end - cuts_begin);
if (sorted_column.size() <= num_bins) {
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
// First check the inputs are unique
int num_unique =
std::set<float>(sorted_column.begin(), sorted_column.end()).size();
EXPECT_EQ(num_unique, sorted_column.size());
for (auto i = 0ull; i < sorted_column.size(); i++) {
ASSERT_EQ(cuts.SearchBin(sorted_column[i], column_idx),
cuts.Ptrs()[column_idx] + i);
int i = 0;
for (auto v : unique) {
ASSERT_EQ(cuts.SearchBin(v, column_idx), cuts.Ptrs()[column_idx] + i);
i++;
}
}
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, num_bins);
TestRank(column_cuts, sorted_column);
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, num_bins);
TestRank(column_cuts, sorted_column,sorted_weights);
}
}
// x is dense and row major
inline void ValidateCuts(const HistogramCuts& cuts, std::vector<float>& x,
int num_rows, int num_columns,
inline void ValidateCuts(const HistogramCuts& cuts, DMatrix* dmat,
int num_bins) {
for (auto i = 0; i < num_columns; i++) {
// Extract the column
std::vector<float> column(num_rows);
for (auto j = 0; j < num_rows; j++) {
column[j] = x[j*num_columns + i];
}
ValidateColumn(cuts,i, column, num_bins);
}
// Collect data into columns
std::vector<std::vector<float>> columns(dmat->Info().num_col_);
for (auto& batch : dmat->GetBatches<SparsePage>()) {
for (auto i = 0ull; i < batch.Size(); i++) {
for (auto e : batch[i]) {
columns[e.index].push_back(e.fvalue);
}
}
}
// Sort
for (auto i = 0ull; i < columns.size(); i++) {
auto& col = columns.at(i);
const auto& w = dmat->Info().weights_.HostVector();
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);
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);
}
}
} // namespace common