-
Notifications
You must be signed in to change notification settings - Fork 3.8k
/
feature_group.h
631 lines (586 loc) · 22.3 KB
/
feature_group.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
/*!
* Copyright (c) 2017 Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See LICENSE file in the project root for
* license information.
*/
#ifndef LIGHTGBM_FEATURE_GROUP_H_
#define LIGHTGBM_FEATURE_GROUP_H_
#include <LightGBM/bin.h>
#include <LightGBM/meta.h>
#include <LightGBM/utils/random.h>
#include <cstdio>
#include <memory>
#include <vector>
namespace LightGBM {
class Dataset;
class DatasetLoader;
struct TrainingShareStates;
class MultiValBinWrapper;
/*! \brief Using to store data and providing some operations on one feature
* group*/
class FeatureGroup {
public:
friend Dataset;
friend DatasetLoader;
friend TrainingShareStates;
friend MultiValBinWrapper;
/*!
* \brief Constructor
* \param num_feature number of features of this group
* \param bin_mappers Bin mapper for features
* \param num_data Total number of data
* \param is_enable_sparse True if enable sparse feature
*/
FeatureGroup(int num_feature, int8_t is_multi_val,
std::vector<std::unique_ptr<BinMapper>>* bin_mappers,
data_size_t num_data, int group_id) :
num_feature_(num_feature), is_multi_val_(is_multi_val > 0), is_sparse_(false) {
CHECK_EQ(static_cast<int>(bin_mappers->size()), num_feature);
auto& ref_bin_mappers = *bin_mappers;
double sum_sparse_rate = 0.0f;
for (int i = 0; i < num_feature_; ++i) {
bin_mappers_.emplace_back(ref_bin_mappers[i].release());
sum_sparse_rate += bin_mappers_.back()->sparse_rate();
}
sum_sparse_rate /= num_feature_;
int offset = 1;
is_dense_multi_val_ = false;
if (sum_sparse_rate < MultiValBin::multi_val_bin_sparse_threshold && is_multi_val_) {
// use dense multi val bin
offset = 0;
is_dense_multi_val_ = true;
}
// use bin at zero to store most_freq_bin only when not using dense multi val bin
num_total_bin_ = offset;
// however, we should force to leave one bin, if dense multi val bin is the first bin
// and its first feature has most freq bin > 0
if (group_id == 0 && num_feature_ > 0 && is_dense_multi_val_ &&
bin_mappers_[0]->GetMostFreqBin() > 0) {
num_total_bin_ = 1;
}
bin_offsets_.emplace_back(num_total_bin_);
for (int i = 0; i < num_feature_; ++i) {
auto num_bin = bin_mappers_[i]->num_bin();
if (bin_mappers_[i]->GetMostFreqBin() == 0) {
num_bin -= offset;
}
num_total_bin_ += num_bin;
bin_offsets_.emplace_back(num_total_bin_);
}
CreateBinData(num_data, is_multi_val_, true, false);
}
FeatureGroup(const FeatureGroup& other, int num_data) {
num_feature_ = other.num_feature_;
is_multi_val_ = other.is_multi_val_;
is_dense_multi_val_ = other.is_dense_multi_val_;
is_sparse_ = other.is_sparse_;
num_total_bin_ = other.num_total_bin_;
bin_offsets_ = other.bin_offsets_;
bin_mappers_.reserve(other.bin_mappers_.size());
for (auto& bin_mapper : other.bin_mappers_) {
bin_mappers_.emplace_back(new BinMapper(*bin_mapper));
}
CreateBinData(num_data, is_multi_val_, !is_sparse_, is_sparse_);
}
FeatureGroup(std::vector<std::unique_ptr<BinMapper>>* bin_mappers,
data_size_t num_data) : num_feature_(1), is_multi_val_(false) {
CHECK_EQ(static_cast<int>(bin_mappers->size()), 1);
// use bin at zero to store default_bin
num_total_bin_ = 1;
is_dense_multi_val_ = false;
bin_offsets_.emplace_back(num_total_bin_);
auto& ref_bin_mappers = *bin_mappers;
for (int i = 0; i < num_feature_; ++i) {
bin_mappers_.emplace_back(ref_bin_mappers[i].release());
auto num_bin = bin_mappers_[i]->num_bin();
if (bin_mappers_[i]->GetMostFreqBin() == 0) {
num_bin -= 1;
}
num_total_bin_ += num_bin;
bin_offsets_.emplace_back(num_total_bin_);
}
CreateBinData(num_data, false, false, false);
}
/*!
* \brief Constructor from memory when data is present
* \param memory Pointer of memory
* \param num_all_data Number of global data
* \param local_used_indices Local used indices, empty means using all data
* \param group_id Id of group
*/
FeatureGroup(const void* memory,
data_size_t num_all_data,
const std::vector<data_size_t>& local_used_indices,
int group_id) {
// Load the definition schema first
const char* memory_ptr = LoadDefinitionFromMemory(memory, group_id);
// Allocate memory for the data
data_size_t num_data = num_all_data;
if (!local_used_indices.empty()) {
num_data = static_cast<data_size_t>(local_used_indices.size());
}
AllocateBins(num_data);
// Now load the actual data
if (is_multi_val_) {
for (int i = 0; i < num_feature_; ++i) {
multi_bin_data_[i]->LoadFromMemory(memory_ptr, local_used_indices);
memory_ptr += multi_bin_data_[i]->SizesInByte();
}
} else {
bin_data_->LoadFromMemory(memory_ptr, local_used_indices);
}
}
/*!
* \brief Constructor from definition in memory (without data)
* \param memory Pointer of memory
* \param local_used_indices Local used indices, empty means using all data
*/
FeatureGroup(const void* memory, data_size_t num_data, int group_id) {
LoadDefinitionFromMemory(memory, group_id);
AllocateBins(num_data);
}
/*! \brief Destructor */
~FeatureGroup() {}
/*!
* \brief Load the overall definition of the feature group from binary serialized data
* \param memory Pointer of memory
* \param group_id Id of group
*/
const char* LoadDefinitionFromMemory(const void* memory, int group_id) {
const char* memory_ptr = reinterpret_cast<const char*>(memory);
// get is_sparse
is_multi_val_ = *(reinterpret_cast<const bool*>(memory_ptr));
memory_ptr += VirtualFileWriter::AlignedSize(sizeof(is_multi_val_));
is_dense_multi_val_ = *(reinterpret_cast<const bool*>(memory_ptr));
memory_ptr += VirtualFileWriter::AlignedSize(sizeof(is_dense_multi_val_));
is_sparse_ = *(reinterpret_cast<const bool*>(memory_ptr));
memory_ptr += VirtualFileWriter::AlignedSize(sizeof(is_sparse_));
num_feature_ = *(reinterpret_cast<const int*>(memory_ptr));
memory_ptr += VirtualFileWriter::AlignedSize(sizeof(num_feature_));
// get bin mapper(s)
bin_mappers_.clear();
for (int i = 0; i < num_feature_; ++i) {
bin_mappers_.emplace_back(new BinMapper(memory_ptr));
memory_ptr += bin_mappers_[i]->SizesInByte();
}
bin_offsets_.clear();
int offset = 1;
if (is_dense_multi_val_) {
offset = 0;
}
// use bin at zero to store most_freq_bin only when not using dense multi val bin
num_total_bin_ = offset;
// however, we should force to leave one bin, if dense multi val bin is the first bin
// and its first feature has most freq bin > 0
if (group_id == 0 && num_feature_ > 0 && is_dense_multi_val_ &&
bin_mappers_[0]->GetMostFreqBin() > 0) {
num_total_bin_ = 1;
}
bin_offsets_.emplace_back(num_total_bin_);
for (int i = 0; i < num_feature_; ++i) {
auto num_bin = bin_mappers_[i]->num_bin();
if (bin_mappers_[i]->GetMostFreqBin() == 0) {
num_bin -= offset;
}
num_total_bin_ += num_bin;
bin_offsets_.emplace_back(num_total_bin_);
}
return memory_ptr;
}
/*!
* \brief Allocate the bins
* \param num_all_data Number of global data
*/
inline void AllocateBins(data_size_t num_data) {
if (is_multi_val_) {
for (int i = 0; i < num_feature_; ++i) {
int addi = bin_mappers_[i]->GetMostFreqBin() == 0 ? 0 : 1;
if (bin_mappers_[i]->sparse_rate() >= kSparseThreshold) {
multi_bin_data_.emplace_back(Bin::CreateSparseBin(num_data, bin_mappers_[i]->num_bin() + addi));
} else {
multi_bin_data_.emplace_back(Bin::CreateDenseBin(num_data, bin_mappers_[i]->num_bin() + addi));
}
}
} else {
if (is_sparse_) {
bin_data_.reset(Bin::CreateSparseBin(num_data, num_total_bin_));
} else {
bin_data_.reset(Bin::CreateDenseBin(num_data, num_total_bin_));
}
}
}
/*!
* \brief Initialize for pushing in a streaming fashion. By default, no action needed.
* \param num_thread The number of external threads that will be calling the push APIs
* \param omp_max_threads The maximum number of OpenMP threads to allocate for
*/
void InitStreaming(int32_t num_thread, int32_t omp_max_threads) {
if (is_multi_val_) {
for (int i = 0; i < num_feature_; ++i) {
multi_bin_data_[i]->InitStreaming(num_thread, omp_max_threads);
}
} else {
bin_data_->InitStreaming(num_thread, omp_max_threads);
}
}
/*!
* \brief Push one record, will auto convert to bin and push to bin data
* \param tid Thread id
* \param sub_feature_idx Index of the subfeature
* \param line_idx Index of record
* \param value feature value of record
*/
inline void PushData(int tid, int sub_feature_idx, data_size_t line_idx, double value) {
uint32_t bin = bin_mappers_[sub_feature_idx]->ValueToBin(value);
if (bin == bin_mappers_[sub_feature_idx]->GetMostFreqBin()) {
return;
}
if (bin_mappers_[sub_feature_idx]->GetMostFreqBin() == 0) {
bin -= 1;
}
if (is_multi_val_) {
multi_bin_data_[sub_feature_idx]->Push(tid, line_idx, bin + 1);
} else {
bin += bin_offsets_[sub_feature_idx];
bin_data_->Push(tid, line_idx, bin);
}
}
void ReSize(int num_data) {
if (!is_multi_val_) {
bin_data_->ReSize(num_data);
} else {
for (int i = 0; i < num_feature_; ++i) {
multi_bin_data_[i]->ReSize(num_data);
}
}
}
inline void CopySubrow(const FeatureGroup* full_feature, const data_size_t* used_indices, data_size_t num_used_indices) {
if (!is_multi_val_) {
bin_data_->CopySubrow(full_feature->bin_data_.get(), used_indices, num_used_indices);
} else {
for (int i = 0; i < num_feature_; ++i) {
multi_bin_data_[i]->CopySubrow(full_feature->multi_bin_data_[i].get(), used_indices, num_used_indices);
}
}
}
inline void CopySubrowByCol(const FeatureGroup* full_feature, const data_size_t* used_indices, data_size_t num_used_indices, int fidx) {
if (!is_multi_val_) {
bin_data_->CopySubrow(full_feature->bin_data_.get(), used_indices, num_used_indices);
} else {
multi_bin_data_[fidx]->CopySubrow(full_feature->multi_bin_data_[fidx].get(), used_indices, num_used_indices);
}
}
void AddFeaturesFrom(const FeatureGroup* other, int group_id) {
CHECK(is_multi_val_);
CHECK(other->is_multi_val_);
// every time when new features are added, we need to reconsider sparse or dense
double sum_sparse_rate = 0.0f;
for (int i = 0; i < num_feature_; ++i) {
sum_sparse_rate += bin_mappers_[i]->sparse_rate();
}
for (int i = 0; i < other->num_feature_; ++i) {
sum_sparse_rate += other->bin_mappers_[i]->sparse_rate();
}
sum_sparse_rate /= (num_feature_ + other->num_feature_);
int offset = 1;
is_dense_multi_val_ = false;
if (sum_sparse_rate < MultiValBin::multi_val_bin_sparse_threshold && is_multi_val_) {
// use dense multi val bin
offset = 0;
is_dense_multi_val_ = true;
}
bin_offsets_.clear();
num_total_bin_ = offset;
// however, we should force to leave one bin, if dense multi val bin is the first bin
// and its first feature has most freq bin > 0
if (group_id == 0 && num_feature_ > 0 && is_dense_multi_val_ &&
bin_mappers_[0]->GetMostFreqBin() > 0) {
num_total_bin_ = 1;
}
bin_offsets_.emplace_back(num_total_bin_);
for (int i = 0; i < num_feature_; ++i) {
auto num_bin = bin_mappers_[i]->num_bin();
if (bin_mappers_[i]->GetMostFreqBin() == 0) {
num_bin -= offset;
}
num_total_bin_ += num_bin;
bin_offsets_.emplace_back(num_total_bin_);
}
for (int i = 0; i < other->num_feature_; ++i) {
const auto& other_bin_mapper = other->bin_mappers_[i];
bin_mappers_.emplace_back(new BinMapper(*other_bin_mapper));
auto num_bin = other_bin_mapper->num_bin();
if (other_bin_mapper->GetMostFreqBin() == 0) {
num_bin -= offset;
}
num_total_bin_ += num_bin;
bin_offsets_.emplace_back(num_total_bin_);
multi_bin_data_.emplace_back(other->multi_bin_data_[i]->Clone());
}
num_feature_ += other->num_feature_;
}
inline BinIterator* SubFeatureIterator(int sub_feature) {
uint32_t most_freq_bin = bin_mappers_[sub_feature]->GetMostFreqBin();
if (!is_multi_val_) {
uint32_t min_bin = bin_offsets_[sub_feature];
uint32_t max_bin = bin_offsets_[sub_feature + 1] - 1;
return bin_data_->GetIterator(min_bin, max_bin, most_freq_bin);
} else {
int addi = bin_mappers_[sub_feature]->GetMostFreqBin() == 0 ? 0 : 1;
uint32_t min_bin = 1;
uint32_t max_bin = bin_mappers_[sub_feature]->num_bin() - 1 + addi;
return multi_bin_data_[sub_feature]->GetIterator(min_bin, max_bin,
most_freq_bin);
}
}
inline void FinishLoad() {
if (is_multi_val_) {
OMP_INIT_EX();
#pragma omp parallel for num_threads(OMP_NUM_THREADS()) schedule(guided)
for (int i = 0; i < num_feature_; ++i) {
OMP_LOOP_EX_BEGIN();
multi_bin_data_[i]->FinishLoad();
OMP_LOOP_EX_END();
}
OMP_THROW_EX();
} else {
bin_data_->FinishLoad();
}
}
inline BinIterator* FeatureGroupIterator() {
if (is_multi_val_) {
return nullptr;
}
uint32_t min_bin = bin_offsets_[0];
uint32_t max_bin = bin_offsets_.back() - 1;
uint32_t most_freq_bin = 0;
return bin_data_->GetIterator(min_bin, max_bin, most_freq_bin);
}
inline size_t FeatureGroupSizesInByte() {
return bin_data_->SizesInByte();
}
inline void* FeatureGroupData() {
if (is_multi_val_) {
return nullptr;
}
return bin_data_->get_data();
}
inline data_size_t Split(int sub_feature, const uint32_t* threshold,
int num_threshold, bool default_left,
const data_size_t* data_indices, data_size_t cnt,
data_size_t* lte_indices,
data_size_t* gt_indices) const {
uint32_t default_bin = bin_mappers_[sub_feature]->GetDefaultBin();
uint32_t most_freq_bin = bin_mappers_[sub_feature]->GetMostFreqBin();
if (!is_multi_val_) {
uint32_t min_bin = bin_offsets_[sub_feature];
uint32_t max_bin = bin_offsets_[sub_feature + 1] - 1;
if (bin_mappers_[sub_feature]->bin_type() == BinType::NumericalBin) {
auto missing_type = bin_mappers_[sub_feature]->missing_type();
if (num_feature_ == 1) {
return bin_data_->Split(max_bin, default_bin, most_freq_bin,
missing_type, default_left, *threshold,
data_indices, cnt, lte_indices, gt_indices);
} else {
return bin_data_->Split(min_bin, max_bin, default_bin, most_freq_bin,
missing_type, default_left, *threshold,
data_indices, cnt, lte_indices, gt_indices);
}
} else {
if (num_feature_ == 1) {
return bin_data_->SplitCategorical(max_bin, most_freq_bin, threshold,
num_threshold, data_indices, cnt,
lte_indices, gt_indices);
} else {
return bin_data_->SplitCategorical(
min_bin, max_bin, most_freq_bin, threshold, num_threshold,
data_indices, cnt, lte_indices, gt_indices);
}
}
} else {
int addi = bin_mappers_[sub_feature]->GetMostFreqBin() == 0 ? 0 : 1;
uint32_t max_bin = bin_mappers_[sub_feature]->num_bin() - 1 + addi;
if (bin_mappers_[sub_feature]->bin_type() == BinType::NumericalBin) {
auto missing_type = bin_mappers_[sub_feature]->missing_type();
return multi_bin_data_[sub_feature]->Split(
max_bin, default_bin, most_freq_bin, missing_type, default_left,
*threshold, data_indices, cnt, lte_indices, gt_indices);
} else {
return multi_bin_data_[sub_feature]->SplitCategorical(
max_bin, most_freq_bin, threshold, num_threshold, data_indices, cnt,
lte_indices, gt_indices);
}
}
}
/*!
* \brief From bin to feature value
* \param bin
* \return FeatureGroup value of this bin
*/
inline double BinToValue(int sub_feature_idx, uint32_t bin) const {
return bin_mappers_[sub_feature_idx]->BinToValue(bin);
}
/*!
* \brief Write to binary stream
* \param writer Writer
* \param include_data Whether to write data (true) or just header information (false)
*/
void SerializeToBinary(BinaryWriter* writer, bool include_data = true) const {
writer->AlignedWrite(&is_multi_val_, sizeof(is_multi_val_));
writer->AlignedWrite(&is_dense_multi_val_, sizeof(is_dense_multi_val_));
writer->AlignedWrite(&is_sparse_, sizeof(is_sparse_));
writer->AlignedWrite(&num_feature_, sizeof(num_feature_));
for (int i = 0; i < num_feature_; ++i) {
bin_mappers_[i]->SaveBinaryToFile(writer);
}
if (include_data) {
if (is_multi_val_) {
for (int i = 0; i < num_feature_; ++i) {
multi_bin_data_[i]->SaveBinaryToFile(writer);
}
} else {
bin_data_->SaveBinaryToFile(writer);
}
}
}
/*!
* \brief Get sizes in byte of this object
*/
size_t SizesInByte(bool include_data = true) const {
size_t ret = VirtualFileWriter::AlignedSize(sizeof(is_multi_val_)) +
VirtualFileWriter::AlignedSize(sizeof(is_dense_multi_val_)) +
VirtualFileWriter::AlignedSize(sizeof(is_sparse_)) +
VirtualFileWriter::AlignedSize(sizeof(num_feature_));
for (int i = 0; i < num_feature_; ++i) {
ret += bin_mappers_[i]->SizesInByte();
}
if (include_data) {
if (!is_multi_val_) {
ret += bin_data_->SizesInByte();
} else {
for (int i = 0; i < num_feature_; ++i) {
ret += multi_bin_data_[i]->SizesInByte();
}
}
}
return ret;
}
/*! \brief Disable copy */
FeatureGroup& operator=(const FeatureGroup&) = delete;
/*! \brief Deep copy */
FeatureGroup(const FeatureGroup& other, bool should_handle_dense_mv,
int group_id) {
num_feature_ = other.num_feature_;
is_multi_val_ = other.is_multi_val_;
is_dense_multi_val_ = other.is_dense_multi_val_;
is_sparse_ = other.is_sparse_;
num_total_bin_ = other.num_total_bin_;
bin_offsets_ = other.bin_offsets_;
bin_mappers_.reserve(other.bin_mappers_.size());
for (auto& bin_mapper : other.bin_mappers_) {
bin_mappers_.emplace_back(new BinMapper(*bin_mapper));
}
if (!is_multi_val_) {
bin_data_.reset(other.bin_data_->Clone());
} else {
multi_bin_data_.clear();
for (int i = 0; i < num_feature_; ++i) {
multi_bin_data_.emplace_back(other.multi_bin_data_[i]->Clone());
}
}
if (should_handle_dense_mv && is_dense_multi_val_ && group_id > 0) {
// this feature group was the first feature group, but now no longer is,
// so we need to eliminate its special empty bin for multi val dense bin
if (bin_mappers_[0]->GetMostFreqBin() > 0 && bin_offsets_[0] == 1) {
for (size_t i = 0; i < bin_offsets_.size(); ++i) {
bin_offsets_[i] -= 1;
}
num_total_bin_ -= 1;
}
}
}
const void* GetColWiseData(const int sub_feature_index,
uint8_t* bit_type,
bool* is_sparse,
std::vector<BinIterator*>* bin_iterator,
const int num_threads) const {
if (sub_feature_index >= 0) {
CHECK(is_multi_val_);
return multi_bin_data_[sub_feature_index]->GetColWiseData(bit_type, is_sparse, bin_iterator, num_threads);
} else {
CHECK(!is_multi_val_);
return bin_data_->GetColWiseData(bit_type, is_sparse, bin_iterator, num_threads);
}
}
const void* GetColWiseData(const int sub_feature_index,
uint8_t* bit_type,
bool* is_sparse,
BinIterator** bin_iterator) const {
if (sub_feature_index >= 0) {
CHECK(is_multi_val_);
return multi_bin_data_[sub_feature_index]->GetColWiseData(bit_type, is_sparse, bin_iterator);
} else {
CHECK(!is_multi_val_);
return bin_data_->GetColWiseData(bit_type, is_sparse, bin_iterator);
}
}
uint32_t feature_max_bin(const int sub_feature_index) {
if (!is_multi_val_) {
return bin_offsets_[sub_feature_index + 1] - 1;
} else {
int addi = bin_mappers_[sub_feature_index]->GetMostFreqBin() == 0 ? 0 : 1;
return bin_mappers_[sub_feature_index]->num_bin() - 1 + addi;
}
}
uint32_t feature_min_bin(const int sub_feature_index) {
if (!is_multi_val_) {
return bin_offsets_[sub_feature_index];
} else {
return 1;
}
}
private:
void CreateBinData(int num_data, bool is_multi_val, bool force_dense, bool force_sparse) {
if (is_multi_val) {
multi_bin_data_.clear();
for (int i = 0; i < num_feature_; ++i) {
int addi = bin_mappers_[i]->GetMostFreqBin() == 0 ? 0 : 1;
if (bin_mappers_[i]->sparse_rate() >= kSparseThreshold) {
multi_bin_data_.emplace_back(Bin::CreateSparseBin(
num_data, bin_mappers_[i]->num_bin() + addi));
} else {
multi_bin_data_.emplace_back(
Bin::CreateDenseBin(num_data, bin_mappers_[i]->num_bin() + addi));
}
}
is_multi_val_ = true;
} else {
if (force_sparse ||
(!force_dense && num_feature_ == 1 &&
bin_mappers_[0]->sparse_rate() >= kSparseThreshold)) {
is_sparse_ = true;
bin_data_.reset(Bin::CreateSparseBin(num_data, num_total_bin_));
} else {
is_sparse_ = false;
bin_data_.reset(Bin::CreateDenseBin(num_data, num_total_bin_));
}
is_multi_val_ = false;
}
}
/*! \brief Number of features */
int num_feature_;
/*! \brief Bin mapper for sub features */
std::vector<std::unique_ptr<BinMapper>> bin_mappers_;
/*! \brief Bin offsets for sub features */
std::vector<uint32_t> bin_offsets_;
/*! \brief Bin data of this feature */
std::unique_ptr<Bin> bin_data_;
std::vector<std::unique_ptr<Bin>> multi_bin_data_;
/*! \brief True if this feature is sparse */
bool is_multi_val_;
bool is_dense_multi_val_;
bool is_sparse_;
int num_total_bin_;
};
} // namespace LightGBM
#endif // LIGHTGBM_FEATURE_GROUP_H_