refactor computing max_cuts

CPPFImdlp.cpp

@@ -50,6 +50,13 @@ namespace mdlp {
         indices = sortIndices(X_, y_);
         metrics.setData(y, indices);
         computeCutPoints(0, X.size(), 1);
+        sort(cutPoints.begin(), cutPoints.end());
+        if (num_cut_points > 0) {
+            // Select the best (with lower entropy) cut points
+            while (cutPoints.size() > num_cut_points) {
+                resizeCutPoints();
+            }
+        }
     }
 
     pair<precision_t, size_t> CPPFImdlp::valueCutPoint(size_t start, size_t cut, size_t end) {
@@ -87,8 +94,6 @@ namespace mdlp {
     void CPPFImdlp::computeCutPoints(size_t start, size_t end, int depth_) {
         size_t cut;
         pair<precision_t, size_t> result;
-        if (cutPoints.size() == num_cut_points)
-            return;
         // Check if the interval length and the depth are Ok
         if (end - start < min_length || depth_ > max_depth)
             return;
@@ -174,12 +179,24 @@ namespace mdlp {
         return idx;
     }
 
-    cutPoints_t CPPFImdlp::getCutPoints() {
-        sort(cutPoints.begin(), cutPoints.end());
-        return cutPoints;
-    }
-
-    int CPPFImdlp::get_depth() const {
-        return depth;
+    void CPPFImdlp::resizeCutPoints() {
+        //Compute entropy of each of the whole cutpoint set and discards the biggest value
+        precision_t maxEntropy = 0;
+        precision_t entropy;
+        size_t maxEntropyIdx = 0;
+        size_t begin = 0;
+        size_t end;
+        for (size_t idx = 0; idx < cutPoints.size(); idx++) {
+            end = begin;
+            while (X[indices[end]] < cutPoints[idx] && end < X.size())
+                end++;
+            entropy = metrics.entropy(begin, end);
+            if (entropy > maxEntropy) {
+                maxEntropy = entropy;
+                maxEntropyIdx = idx;
+            }
+            begin = end;
+        }
+        cutPoints.erase(cutPoints.begin() + static_cast<long>(maxEntropyIdx));
     }
 }