64c8f6fa6d
It has been reported that new parallel algorithm (#2493) results in excessive message usage (see issue #2326). Until issues are resolved, XGBoost should use the old parallel algorithm by default. The user would have to specify `enable_feature_grouping=1` manually to enable the new algorithm.
65 lines
3.1 KiB
C++
65 lines
3.1 KiB
C++
/*!
|
|
* Copyright 2017 by Contributors
|
|
* \file updater_fast_hist.h
|
|
* \brief parameters for histogram-based training
|
|
* \author Philip Cho, Tianqi Chen
|
|
*/
|
|
#ifndef XGBOOST_TREE_FAST_HIST_PARAM_H_
|
|
#define XGBOOST_TREE_FAST_HIST_PARAM_H_
|
|
|
|
namespace xgboost {
|
|
namespace tree {
|
|
|
|
/*! \brief training parameters for histogram-based training */
|
|
struct FastHistParam : public dmlc::Parameter<FastHistParam> {
|
|
// integral data type to be used with columnar data storage
|
|
enum class DataType { uint8 = 1, uint16 = 2, uint32 = 4 };
|
|
int colmat_dtype;
|
|
// percentage threshold for treating a feature as sparse
|
|
// e.g. 0.2 indicates a feature with fewer than 20% nonzeros is considered sparse
|
|
double sparse_threshold;
|
|
// use feature grouping? (default yes)
|
|
int enable_feature_grouping;
|
|
// when grouping features, how many "conflicts" to allow.
|
|
// conflict is when an instance has nonzero values for two or more features
|
|
// default is 0, meaning features should be strictly complementary
|
|
double max_conflict_rate;
|
|
// when grouping features, how much effort to expend to prevent singleton groups
|
|
// we'll try to insert each feature into existing groups before creating a new group
|
|
// for that feature; to save time, only up to (max_search_group) of existing groups
|
|
// will be considered. If set to zero, ALL existing groups will be examined
|
|
unsigned max_search_group;
|
|
|
|
// declare the parameters
|
|
DMLC_DECLARE_PARAMETER(FastHistParam) {
|
|
DMLC_DECLARE_FIELD(colmat_dtype)
|
|
.set_default(static_cast<int>(DataType::uint32))
|
|
.add_enum("uint8", static_cast<int>(DataType::uint8))
|
|
.add_enum("uint16", static_cast<int>(DataType::uint16))
|
|
.add_enum("uint32", static_cast<int>(DataType::uint32))
|
|
.describe("Integral data type to be used with columnar data storage."
|
|
"May carry marginal performance implications. Reserved for "
|
|
"advanced use");
|
|
DMLC_DECLARE_FIELD(sparse_threshold).set_range(0, 1.0).set_default(0.2)
|
|
.describe("percentage threshold for treating a feature as sparse");
|
|
DMLC_DECLARE_FIELD(enable_feature_grouping).set_lower_bound(0).set_default(0)
|
|
.describe("if >0, enable feature grouping to ameliorate work imbalance "
|
|
"among worker threads");
|
|
DMLC_DECLARE_FIELD(max_conflict_rate).set_range(0, 1.0).set_default(0)
|
|
.describe("when grouping features, how many \"conflicts\" to allow."
|
|
"conflict is when an instance has nonzero values for two or more features."
|
|
"default is 0, meaning features should be strictly complementary.");
|
|
DMLC_DECLARE_FIELD(max_search_group).set_lower_bound(0).set_default(100)
|
|
.describe("when grouping features, how much effort to expend to prevent "
|
|
"singleton groups. We'll try to insert each feature into existing "
|
|
"groups before creating a new group for that feature; to save time, "
|
|
"only up to (max_search_group) of existing groups will be "
|
|
"considered. If set to zero, ALL existing groups will be examined.");
|
|
}
|
|
};
|
|
|
|
} // namespace tree
|
|
} // namespace xgboost
|
|
|
|
#endif // XGBOOST_TREE_FAST_HIST_PARAM_H_
|