From e29512897315cbc6092e668c4f48bb6ef62f3fd7 Mon Sep 17 00:00:00 2001
From: tqchen <tianqi.tchen@gmail.com>
Date: Wed, 15 Oct 2014 14:30:09 -0700
Subject: [PATCH] add bitmap .

---
 src/tree/updater.cpp              |  2 ++
 src/tree/updater_colmaker-inl.hpp | 41 ++++++++++++++++++++++---------
 2 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/src/tree/updater.cpp b/src/tree/updater.cpp
index 5879b2bbd..e2c530142 100644
--- a/src/tree/updater.cpp
+++ b/src/tree/updater.cpp
@@ -5,6 +5,7 @@
 #include "./updater_prune-inl.hpp"
 #include "./updater_refresh-inl.hpp"
 #include "./updater_colmaker-inl.hpp"
+#include "./updater_distcol-inl.hpp"
 
 namespace xgboost {
 namespace tree {
@@ -12,6 +13,7 @@ IUpdater* CreateUpdater(const char *name) {
   using namespace std;
   if (!strcmp(name, "prune")) return new TreePruner();
   if (!strcmp(name, "refresh")) return new TreeRefresher<GradStats>();
+  if (!strcmp(name, "distcol")) return new DistColMaker<GradStats>();
   if (!strcmp(name, "grow_colmaker")) return new ColMaker<GradStats>();
   if (!strcmp(name, "grow_colmaker5")) return new ColMaker< CVGradStats<5> >();
   if (!strcmp(name, "grow_colmaker3")) return new ColMaker< CVGradStats<3> >();
diff --git a/src/tree/updater_colmaker-inl.hpp b/src/tree/updater_colmaker-inl.hpp
index 9c2740264..596c8c8f5 100644
--- a/src/tree/updater_colmaker-inl.hpp
+++ b/src/tree/updater_colmaker-inl.hpp
@@ -36,10 +36,11 @@ class ColMaker: public IUpdater {
       Builder builder(param);
       builder.Update(gpair, p_fmat, info, trees[i]);
     }
+
     param.learning_rate = lr;
   }
 
- private:
+ protected:
   // training parameter
   TrainParam param;
   // data structure
@@ -108,7 +109,7 @@ class ColMaker: public IUpdater {
       }
     }
 
-   private:
+   protected:
     // initialize temp data structure
     inline void InitData(const std::vector<bst_gpair> &gpair,
                          const IFMatrix &fmat,
@@ -409,7 +410,7 @@ class ColMaker: public IUpdater {
       }
     }
     // update the solution candidate 
-    virtual void UpdateSolution(const ColBatch &batch,                                
+    virtual void UpdateSolution(const ColBatch &batch,
                                 const std::vector<bst_gpair> &gpair,
                                 const IFMatrix &fmat,
                                 const BoosterInfo &info) {
@@ -463,12 +464,11 @@ class ColMaker: public IUpdater {
         this->UpdateSolution(iter->Value(), gpair, *p_fmat, info);
       }
       // after this each thread's stemp will get the best candidates, aggregate results
+      this->SyncBestSolution(qexpand);
+      // get the best result, we can synchronize the solution
       for (size_t i = 0; i < qexpand.size(); ++i) {
         const int nid = qexpand[i];
-        NodeEntry &e = snode[nid];
-        for (int tid = 0; tid < this->nthread; ++tid) {
-          e.best.Update(stemp[tid][nid].best);
-        }
+        NodeEntry &e = snode[nid];        
         // now we know the solution in snode[nid], set split
         if (e.best.loss_chg > rt_eps) {
           p_tree->AddChilds(nid);
@@ -476,9 +476,8 @@ class ColMaker: public IUpdater {
         } else {
           (*p_tree)[nid].set_leaf(e.weight * param.learning_rate);
         }
-      }
+      } 
     }
-
     // reset position of each data points after split is created in the tree
     inline void ResetPosition(const std::vector<int> &qexpand, IFMatrix *p_fmat, const RegTree &tree) {
       const std::vector<bst_uint> &rowset = p_fmat->buffered_rowset();
@@ -490,18 +489,36 @@ class ColMaker: public IUpdater {
         const int nid = position[ridx];
         if (nid >= 0) {
           if (tree[nid].is_leaf()) {
-            position[ridx] = -1;
+            position[ridx] = - nid - 1;
           } else {
             // push to default branch, correct latter
             position[ridx] = tree[nid].default_left() ? tree[nid].cleft(): tree[nid].cright();
           }
         }
       }
+      // set the positions in the nondefault places
+      this->SetNonDefaultPosition(qexpand, p_fmat, tree);
+    }
+    // customization part
+    // synchronize the best solution of each node
+    virtual void SyncBestSolution(const std::vector<int> &qexpand) {
+      for (size_t i = 0; i < qexpand.size(); ++i) {
+        const int nid = qexpand[i];
+        NodeEntry &e = snode[nid];
+        for (int tid = 0; tid < this->nthread; ++tid) {
+          e.best.Update(stemp[tid][nid].best);
+        }
+      }
+    }
+    virtual void SetNonDefaultPosition(const std::vector<int> &qexpand,
+                                       IFMatrix *p_fmat, const RegTree &tree) {
       // step 2, classify the non-default data into right places
       std::vector<unsigned> fsplits;
       for (size_t i = 0; i < qexpand.size(); ++i) {
         const int nid = qexpand[i];
-        if (!tree[nid].is_leaf()) fsplits.push_back(tree[nid].split_index());
+        if (!tree[nid].is_leaf()) {
+          fsplits.push_back(tree[nid].split_index());
+        }
       }
       std::sort(fsplits.begin(), fsplits.end());
       fsplits.resize(std::unique(fsplits.begin(), fsplits.end()) - fsplits.begin());
@@ -518,7 +535,7 @@ class ColMaker: public IUpdater {
             const bst_uint ridx = col[j].index;
             const float fvalue = col[j].fvalue;
             int nid = position[ridx];
-            if (nid == -1) continue;
+            if (nid < 0) continue;
             // go back to parent, correct those who are not default
             nid = tree[nid].parent();
             if (tree[nid].split_index() == fid) {