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/
histogram_helpers.h
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/
histogram_helpers.h
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#if defined(__CUDACC__)
#include "../../src/data/ellpack_page.cuh"
#endif
namespace xgboost {
#if defined(__CUDACC__)
namespace {
class HistogramCutsWrapper : public common::HistogramCuts {
public:
using SuperT = common::HistogramCuts;
void SetValues(std::vector<float> cuts) {
SuperT::cut_values_.HostVector() = std::move(cuts);
}
void SetPtrs(std::vector<uint32_t> ptrs) {
SuperT::cut_ptrs_.HostVector() = std::move(ptrs);
}
void SetMins(std::vector<float> mins) {
SuperT::min_vals_.HostVector() = std::move(mins);
}
};
} // anonymous namespace
inline std::unique_ptr<EllpackPageImpl> BuildEllpackPage(
int n_rows, int n_cols, bst_float sparsity= 0) {
auto dmat = RandomDataGenerator(n_rows, n_cols, sparsity).Seed(3).GenerateDMatrix();
const SparsePage& batch = *dmat->GetBatches<xgboost::SparsePage>().begin();
HistogramCutsWrapper cmat;
cmat.SetPtrs({0, 3, 6, 9, 12, 15, 18, 21, 24});
// 24 cut fields, 3 cut fields for each feature (column).
cmat.SetValues({0.30f, 0.67f, 1.64f,
0.32f, 0.77f, 1.95f,
0.29f, 0.70f, 1.80f,
0.32f, 0.75f, 1.85f,
0.18f, 0.59f, 1.69f,
0.25f, 0.74f, 2.00f,
0.26f, 0.74f, 1.98f,
0.26f, 0.71f, 1.83f});
cmat.SetMins({0.1f, 0.2f, 0.3f, 0.1f, 0.2f, 0.3f, 0.2f, 0.2f});
bst_row_t row_stride = 0;
const auto &offset_vec = batch.offset.ConstHostVector();
for (size_t i = 1; i < offset_vec.size(); ++i) {
row_stride = std::max(row_stride, offset_vec[i] - offset_vec[i-1]);
}
auto page = std::unique_ptr<EllpackPageImpl>(
new EllpackPageImpl(0, cmat, batch, dmat->IsDense(), row_stride, {}));
return page;
}
#endif
} // namespace xgboost