diff --git a/src/mykdtree.hpp b/src/mykdtree.hpp
index 10c96b4..3b27ed3 100644
--- a/src/mykdtree.hpp
+++ b/src/mykdtree.hpp
@@ -35,6 +35,9 @@ namespace CosmoTool {
     KDCell<N,ValType,CType> *value;
     KDTreeNode<N,ValType,CType> *children[2];
     typename KDDef<N,CType>::KDCoordinates minBound, maxBound;
+#ifdef __KD_TREE_NUMNODES
+    uint32_t numNodes;
+#endif
   };
 
   template<int N, typename ValType, typename CType = ComputePrecision>
@@ -105,6 +108,17 @@ namespace CosmoTool {
 
     uint32_t countActives() const;
 
+#ifdef __KD_TREE_NUMNODES
+    uint32_t getNumberInNode(const Node *n) const { return n->numNodes; }
+#else
+    uint32_t getNumberInNode(const Node *n) const {
+      if (n == 0) 
+        return 0;
+      return 1+getNumberInNode(n->children[0])+getNumberInNode(n->children[1]);
+    }
+#endif
+
+
   protected:
     Node *nodes;
     uint32_t numNodes;
@@ -124,7 +138,7 @@ namespace CosmoTool {
 				    int level)
       throw (NotEnoughCells);
 
-    CoordType computeDistance(Cell *cell, const coords& x);
+    CoordType computeDistance(const Cell *cell, const coords& x) const;
     void recursiveNearest(Node *node,
 			  int level,
 			  const coords& x,
@@ -132,6 +146,7 @@ namespace CosmoTool {
 			  Cell*& cell);
     void recursiveMultipleNearest(RecursionMultipleInfo<N,ValType,CType>& info, Node *node,
 				  int level);    
+
   };
 
   template<int N, typename T, typename CType>
diff --git a/src/mykdtree.tcc b/src/mykdtree.tcc
index 183e48e..7faae26 100644
--- a/src/mykdtree.tcc
+++ b/src/mykdtree.tcc
@@ -2,6 +2,7 @@
 #include <algorithm>
 #include <limits>
 #include <iostream>
+#include <cassert>
 
 namespace CosmoTool {
 
@@ -53,8 +54,20 @@ namespace CosmoTool {
     lastNode = 0;
     for (int i = 0; i < N; i++)
       {
-	absoluteMin[i] = -std::numeric_limits<typeof (absoluteMin[0])>::max();
-	absoluteMax[i] = std::numeric_limits<typeof (absoluteMax[0])>::max();
+	absoluteMin[i] = std::numeric_limits<typeof (absoluteMin[0])>::max();
+	absoluteMax[i] = -std::numeric_limits<typeof (absoluteMax[0])>::max();
+      }
+    // Find min and max corner
+    for (uint32_t i = 0; i < activeCells; i++)
+      {
+        KDCell<N,ValType,CType> *cell = sortingHelper[i];
+
+        for (int k = 0; k < N; k++) {
+          if (cell->coord[k] < absoluteMin[k])
+            absoluteMin[k] = cell->coord[k];
+          if (cell->coord[k] > absoluteMax[k])
+            absoluteMax[k] = cell->coord[k];
+        }
       }
     
     std::cout << "   rebuilding the tree..." << std::endl;
@@ -208,6 +221,12 @@ namespace CosmoTool {
     node->children[1] = buildTree(cell0+mid+1, Ncells-mid-1, depth, 
 				  tmpBound, maxBound);
 
+#ifdef __KD_TREE_NUMNODES
+    node->numNodes = (node->children[0] != 0) ? node->children[0]->numNodes : 0;
+    node->numNodes += (node->children[1] != 0) ? node->children[1]->numNodes : 0;
+    node->numNodes++;
+#endif
+
     return node;
   }
 
@@ -225,7 +244,7 @@ namespace CosmoTool {
 
   template<int N, typename ValType, typename CType>
   typename KDDef<N,CType>::CoordType
-  KDTree<N,ValType,CType>::computeDistance(Cell *cell, const coords& x)
+  KDTree<N,ValType,CType>::computeDistance(const Cell *cell, const coords& x) const
   {
     CoordType d2 = 0;
 
@@ -410,4 +429,5 @@ namespace CosmoTool {
    //   std::cout << "Traversed = " << info.traversed << std::endl;
  }
 
+
 };