fix bugs in bin finder

include/LightGBM/utils/common.h

@@ -16,18 +16,6 @@ namespace LightGBM {
 
 namespace Common {
 
-template<typename T>
-inline static T Max(const T& a, const T& b) {
-  return a > b ? a : b;
-}
-
-template<typename T>
-inline static T Min(const T& a, const T& b) {
-  return a < b ? a : b;
-}
-
-
-
 inline static std::string& Trim(std::string& str) {
   if (str.size() <= 0) {
     return str;
@@ -329,8 +317,8 @@ inline static std::string Join(const std::vector<T>& strs, size_t start, size_t
   if (end - start <= 0) {
     return std::string("");
   }
-  start = Min<size_t>(start, static_cast<size_t>(strs.size()) - 1);
-  end = Min<size_t>(end, static_cast<size_t>(strs.size()));
+  start = std::min(start, static_cast<size_t>(strs.size()) - 1);
+  end = std::min(end, static_cast<size_t>(strs.size()));
   std::stringstream ss;
   ss << strs[start];
   for (size_t i = start + 1; i < end; ++i) {

src/boosting/dart.cpp

@@ -110,9 +110,9 @@ void DART::DroppingTrees() {
     drop_index_ = random_for_drop_.Sample(iter_, 1);
   }
   // drop trees
-  for (int i: drop_index_) {
+  for (auto i: drop_index_) {
     for (int curr_class = 0; curr_class < num_class_; ++curr_class) {
-      int curr_tree = i * num_class_ + curr_class;
+      auto curr_tree = i * num_class_ + curr_class;
       models_[curr_tree]->Shrinkage(-1.0);
       train_score_updater_->AddScore(models_[curr_tree], curr_class);
     }
@@ -122,9 +122,9 @@ void DART::DroppingTrees() {
 
 void DART::Normalize() {
   double k = static_cast<double>(drop_index_.size());
-  for (int i: drop_index_) {
+  for (auto i: drop_index_) {
     for (int curr_class = 0; curr_class < num_class_; ++curr_class) {
-      int curr_tree = i * num_class_ + curr_class;
+      auto curr_tree = i * num_class_ + curr_class;
       // update validation score
       models_[curr_tree]->Shrinkage(shrinkage_rate_);
       for (auto& score_updater : valid_score_updater_) {

src/boosting/gbdt.cpp

@@ -385,7 +385,7 @@ void GBDT::SaveModelToFile(int num_used_model, bool is_finish, const char* filen
     model_output_file_ << models_[i]->ToString() << std::endl;
   }
 
-  saved_model_size_ = Common::Max(saved_model_size_, rest);
+  saved_model_size_ = std::max(saved_model_size_, rest);
 
   model_output_file_.flush();
   // training finished, can close file

src/io/bin.cpp

@@ -42,29 +42,45 @@ BinMapper::~BinMapper() {
 void BinMapper::FindBin(std::vector<double>* values, size_t total_sample_cnt, int max_bin) {
   std::vector<double>& ref_values = (*values);
   size_t sample_size = total_sample_cnt;
-  size_t zero_cnt = total_sample_cnt - ref_values.size();
+  int zero_cnt = static_cast<int>(total_sample_cnt - ref_values.size());
   // find distinct_values first
   std::vector<double> distinct_values;
   std::vector<int> counts;
 
   std::sort(ref_values.begin(), ref_values.end());
-  // push 0 first
-  if (zero_cnt > 0) {
-    distinct_values.push_back(0.0f);
-    counts.push_back(static_cast<int>(zero_cnt));
+
+  // push zero in the front
+  if (ref_values.size() == 0 || (ref_values[0] > 0.0f && zero_cnt > 0)) {
+    distinct_values.push_back(0);
+    counts.push_back(zero_cnt);
   }
+
   if (ref_values.size() > 0) {
     distinct_values.push_back(ref_values[0]);
     counts.push_back(1);
   }
+
   for (size_t i = 1; i < ref_values.size(); ++i) {
     if (ref_values[i] != ref_values[i - 1]) {
+      if (ref_values[i - 1] == 0.0f) {
+        counts.back() += zero_cnt;
+      } else if (ref_values[i - 1] < 0.0f && ref_values[i] > 0.0f) {
+        distinct_values.push_back(0);
+        counts.push_back(zero_cnt);
+      }
       distinct_values.push_back(ref_values[i]);
       counts.push_back(1);
     } else {
       ++counts.back();
     }
   }
+
+  // push zero in the back
+  if (ref_values.size() > 0 && ref_values.back() < 0.0f && zero_cnt > 0) {
+    distinct_values.push_back(0);
+    counts.push_back(zero_cnt);
+  }
+
   int num_values = static_cast<int>(distinct_values.size());
   int cnt_in_bin0 = 0;
   if (num_values <= max_bin) {
@@ -78,53 +94,38 @@ void BinMapper::FindBin(std::vector<double>* values, size_t total_sample_cnt, in
     cnt_in_bin0 = counts[0];
     bin_upper_bound_[num_values - 1] = std::numeric_limits<double>::infinity();
   } else {
-    double min_lower_bound = std::numeric_limits<double>::infinity();
     // mean size for one bin
     double mean_bin_size = sample_size / static_cast<double>(max_bin);
-    int rest_sample_cnt = static_cast<int>(sample_size);
-    int bin_cnt = 0;
+    std::vector<bool> is_big_count_value(num_values, false);
+    for (int i = 0; i < num_values; ++i) {
+      if (counts[i] >= mean_bin_size) { is_big_count_value[i] = true; }
+    }
     std::vector<double> upper_bounds(max_bin, std::numeric_limits<double>::infinity());
     std::vector<double> lower_bounds(max_bin, std::numeric_limits<double>::infinity());
-    // sort by count, descent
-    Common::SortForPair(counts, distinct_values, 0, true);
-    // fetch big slot as unique bin 
-    while (counts[bin_cnt] > mean_bin_size) {
-      upper_bounds[bin_cnt] = distinct_values[bin_cnt];
-      lower_bounds[bin_cnt] = distinct_values[bin_cnt];
-      if (lower_bounds[bin_cnt] < min_lower_bound) {
-        min_lower_bound = lower_bounds[bin_cnt];
-        cnt_in_bin0 = counts[bin_cnt];
-      }
-      rest_sample_cnt -= counts[bin_cnt];
-      ++bin_cnt;
-    }
-    // process reminder bins
-    if (bin_cnt < max_bin) {
-      // sort rest by values
-      Common::SortForPair<double, int>(distinct_values, counts, bin_cnt, false);
-      mean_bin_size = rest_sample_cnt / static_cast<double>(max_bin - bin_cnt);
-      lower_bounds[bin_cnt] = distinct_values[bin_cnt];
-      int cur_cnt_inbin = 0;
-      for (int i = bin_cnt; i < num_values - 1; ++i) {
-        rest_sample_cnt -= counts[i];
-        cur_cnt_inbin += counts[i];
-        // need a new bin
-        if (cur_cnt_inbin >= mean_bin_size) {
-          upper_bounds[bin_cnt] = distinct_values[i];
-          if (lower_bounds[bin_cnt] < min_lower_bound) {
-            min_lower_bound = lower_bounds[bin_cnt];
-            cnt_in_bin0 = cur_cnt_inbin;
-          }
-          ++bin_cnt;
-          lower_bounds[bin_cnt] = distinct_values[i + 1];
-          if (bin_cnt >= max_bin - 1) break;
-          cur_cnt_inbin = 0;
-          mean_bin_size = rest_sample_cnt / static_cast<double>(max_bin - bin_cnt);
+
+    int rest_sample_cnt = static_cast<int>(sample_size);
+    int bin_cnt = 0;
+    lower_bounds[bin_cnt] = distinct_values[0];
+    int cur_cnt_inbin = 0;
+    for (int i = 0; i < num_values - 1; ++i) {
+      rest_sample_cnt -= counts[i];
+      cur_cnt_inbin += counts[i];
+      // need a new bin
+      if (is_big_count_value[i] || cur_cnt_inbin >= mean_bin_size ||
+        (is_big_count_value[i + 1] && cur_cnt_inbin >= std::max(1.0, mean_bin_size * 0.5f))) {
+        upper_bounds[bin_cnt] = distinct_values[i];
+        if (bin_cnt == 0) {
+          cnt_in_bin0 = cur_cnt_inbin;
         }
+        ++bin_cnt;
+        lower_bounds[bin_cnt] = distinct_values[i + 1];
+        if (bin_cnt >= max_bin - 1) { break; }
+        cur_cnt_inbin = 0;
+        mean_bin_size = rest_sample_cnt / static_cast<double>(max_bin - bin_cnt);
       }
-      cur_cnt_inbin += counts[num_values - 1];
     }
-    Common::SortForPair<double, double>(lower_bounds, upper_bounds, 0, false);
+    //
+    ++bin_cnt;
     // update bin upper bound
     bin_upper_bound_ = new double[bin_cnt];
     num_bin_ = bin_cnt;

src/io/dataset_loader.cpp

@@ -657,7 +657,7 @@ void DatasetLoader::ConstructBinMappersFromTextData(int rank, int num_machines,
 
     start[0] = 0;
     for (int i = 0; i < num_machines - 1; ++i) {
-      len[i] = Common::Min<int>(step, total_num_feature - start[i]);
+      len[i] = std::min(step, total_num_feature - start[i]);
       start[i + 1] = start[i] + len[i];
     }
     len[num_machines - 1] = total_num_feature - start[num_machines - 1];

src/network/linkers.h

 #ifndef LIGHTGBM_NETWORK_LINKERS_H_
 #define LIGHTGBM_NETWORK_LINKERS_H_
 
+
 #include <LightGBM/meta.h>
 #include <LightGBM/config.h>
 #include <LightGBM/network.h>
 
+#include <algorithm>
 #include <chrono>
 #include <ctime>
-
 #ifdef USE_SOCKET
 #include "socket_wrapper.hpp"
 #include <LightGBM/utils/common.h>
@@ -171,9 +172,9 @@ inline const RecursiveHalvingMap& Linkers::recursive_halving_map() {
 inline void Linkers::Recv(int rank, char* data, int len) const {
   int recv_cnt = 0;
   while (recv_cnt < len) {
-    recv_cnt += linkers_[rank]->Recv(data + recv_cnt ,
+    recv_cnt += linkers_[rank]->Recv(data + recv_cnt,
       //len - recv_cnt
-      Common::Min<int>(len - recv_cnt, SocketConfig::kMaxReceiveSize)
+      std::min(len - recv_cnt, SocketConfig::kMaxReceiveSize)
     );
   }
 }

src/network/network.cpp

@@ -54,7 +54,7 @@ void Network::Allreduce(char* input, int input_size, int type_size, char* output
   }
   block_start_[0] = 0;
   for (int i = 0; i < num_machines_ - 1; ++i) {
-    block_len_[i] = Common::Min<int>(step * type_size, input_size - block_start_[i]);
+    block_len_[i] = std::min(step * type_size, input_size - block_start_[i]);
     block_start_[i + 1] = block_start_[i] + block_len_[i];
   }
   block_len_[num_machines_ - 1] = input_size - block_start_[num_machines_ - 1];
@@ -108,7 +108,7 @@ void Network::Allgather(char* input, int all_size, int* block_start, int* block_
   int accumulated_block = 1;
   for (int i = 0; i < bruck_map_.k; ++i) {
     // get current local block size
-    int cur_block_size = Common::Min<int>(1 << i, num_machines_ - accumulated_block);
+    int cur_block_size = std::min(1 << i, num_machines_ - accumulated_block);
     // get out rank
     int out_rank = bruck_map_.out_ranks[i];
     // get send information

src/network/socket_wrapper.hpp

@@ -3,7 +3,7 @@
 #ifdef USE_SOCKET
 
 #if defined(_WIN32)
-
+#define NOMINMAX
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #include <iphlpapi.h>

src/treelearner/serial_tree_learner.cpp

@@ -62,8 +62,8 @@ void SerialTreeLearner::Init(const Dataset* train_data) {
     max_cache_size = static_cast<int>(histogram_pool_size_ * 1024 * 1024 / total_histogram_size);
   }
   // at least need 2 leaves
-  max_cache_size = Common::Max(2, max_cache_size);
-  max_cache_size = Common::Min(max_cache_size, num_leaves_);
+  max_cache_size = std::max(2, max_cache_size);
+  max_cache_size = std::min(max_cache_size, num_leaves_);
   histogram_pool_.ResetSize(max_cache_size, num_leaves_);
 
   auto histogram_create_function = [this]() {