multi_target_tree_model.h

转到此文件的文档。

#ifndef XGBOOST_MULTI_TARGET_TREE_MODEL_H_
#define XGBOOST_MULTI_TARGET_TREE_MODEL_H_
#include <xgboost/base.h> // 用于 bst_node_t, bst_target_t, bst_feature_t
#include <xgboost/context.h> // 用于 Context
#include <xgboost/linalg.h> // 用于 VectorView
#include <xgboost/model.h> // 用于 Model
#include <xgboost/span.h> // 用于 Span

#include <cinttypes> // 用于 uint8_t
#include <cstddef> // 用于 size_t
#include <vector> // 用于 vector

namespace xgboost {
struct TreeParam;
class MultiTargetTree : public Model {
 public
 static bst_node_t constexpr InvalidNodeId() { return -1; }

 private
 TreeParam const* param_;
 std::vector<bst_node_t> left_;
 std::vector<bst_node_t> right_;
 std::vector<bst_node_t> parent_;
 std::vector<bst_feature_t> split_index_;
 std::vector<std::uint8_t> default_left_;
 std::vector<float> split_conds_;
 std::vector<float> weights_;

 [[nodiscard]] linalg::VectorView<float const> NodeWeight(bst_node_t nidx) const {
 auto beg = nidx * this->NumTarget();
 auto v = common::Span<float const>{weights_}.subspan(beg, this->NumTarget());
 return linalg::MakeTensorView(DeviceOrd::CPU(), v, v.size());
 }
 [[nodiscard]] linalg::VectorView<float> NodeWeight(bst_node_t nidx) {
 auto beg = nidx * this->NumTarget();
 auto v = common::Span<float>{weights_}.subspan(beg, this->NumTarget());
 return linalg::MakeTensorView(DeviceOrd::CPU(), v, v.size());
 }

 public
 explicit MultiTargetTree(TreeParam const* param);
 void SetLeaf(bst_node_t nidx, linalg::VectorView<float const> weight);
 void Expand(bst_node_t nidx, bst_feature_t split_idx, float split_cond, bool default_left,
 linalg::VectorView<float const> base_weight,
 linalg::VectorView<float const> left_weight,
 linalg::VectorView<float const> right_weight);

 [[nodiscard]] bool IsLeaf(bst_node_t nidx) const { return left_[nidx] == InvalidNodeId(); }
 [[nodiscard]] bst_node_t Parent(bst_node_t nidx) const { return parent_.at(nidx); }
 [[nodiscard]] bst_node_t LeftChild(bst_node_t nidx) const { return left_.at(nidx); }
 [[nodiscard]] bst_node_t RightChild(bst_node_t nidx) const { return right_.at(nidx); }

 [[nodiscard]] bst_feature_t SplitIndex(bst_node_t nidx) const { return split_index_[nidx]; }
 [[nodiscard]] float SplitCond(bst_node_t nidx) const { return split_conds_[nidx]; }
 [[nodiscard]] bool DefaultLeft(bst_node_t nidx) const { return default_left_[nidx]; }
 [[nodiscard]] bst_node_t DefaultChild(bst_node_t nidx) const {
 return this->DefaultLeft(nidx) ? this->LeftChild(nidx) : this->RightChild(nidx);
 }

 [[nodiscard]] bst_target_t NumTarget() const;

 [[nodiscard]] std::size_t Size() const;

 [[nodiscard]] bst_node_t Depth(bst_node_t nidx) const {
 bst_node_t depth{0};
 while (Parent(nidx) != InvalidNodeId()) {
 ++depth;
 nidx = Parent(nidx);
 }
 return depth;
 }

 [[nodiscard]] linalg::VectorView<float const> LeafValue(bst_node_t nidx) const {
 CHECK(IsLeaf(nidx));
 return this->NodeWeight(nidx);
 }

 void LoadModel(Json const& in) override;
 void SaveModel(Json* out) const override;
};
} // 命名空间 xgboost
#endif // XGBOOST_MULTI_TARGET_TREE_MODEL_H_