[mlpack-svn] r16807 - in mlpack/trunk/src/mlpack/core/tree: binary_space_tree cover_tree rectangle_tree

fastlab-svn at coffeetalk-1.cc.gatech.edu fastlab-svn at coffeetalk-1.cc.gatech.edu
Thu Jul 10 10:02:09 EDT 2014


Author: rcurtin
Date: Thu Jul 10 10:02:09 2014
New Revision: 16807

Log:
Add MinimumBoundDistance().
This represents the minimum distance between the center of a node and any edge
of the bound.  Note that for ball bounds, this is equivalent to the furthest
descendant distance.


Modified:
   mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree.hpp
   mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree_impl.hpp
   mlpack/trunk/src/mlpack/core/tree/cover_tree/cover_tree.hpp
   mlpack/trunk/src/mlpack/core/tree/rectangle_tree/rectangle_tree.hpp

Modified: mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree.hpp
==============================================================================
--- mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree.hpp	(original)
+++ mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree.hpp	Thu Jul 10 10:02:09 2014
@@ -66,8 +66,11 @@
   size_t splitDimension;
   //! The distance from the centroid of this node to the centroid of the parent.
   double parentDistance;
-  //! The worst possible distance to the furthest descendant, cached to speed things up.
+  //! The worst possible distance to the furthest descendant, cached to speed
+  //! things up.
   double furthestDescendantDistance;
+  //! The minimum distance from the center to any edge of the bound.
+  double minimumBoundDistance;
   //! The dataset.
   MatType& dataset;
 
@@ -308,6 +311,9 @@
    */
   double FurthestDescendantDistance() const;
 
+  //! Return the minimum distance from the center of the node to any bound edge.
+  double MinimumBoundDistance() const;
+
   //! Return the distance from the center of this node to the center of the
   //! parent node.
   double ParentDistance() const { return parentDistance; }

Modified: mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree_impl.hpp
==============================================================================
--- mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree_impl.hpp	(original)
+++ mlpack/trunk/src/mlpack/core/tree/binary_space_tree/binary_space_tree_impl.hpp	Thu Jul 10 10:02:09 2014
@@ -238,6 +238,7 @@
     splitDimension(other.splitDimension),
     parentDistance(other.parentDistance),
     furthestDescendantDistance(other.furthestDescendantDistance),
+    minimumBoundDistance(other.minimumBoundDistance),
     dataset(other.dataset)
 {
   // Create left and right children (if any).
@@ -462,6 +463,17 @@
   return furthestDescendantDistance;
 }
 
+//! Return the minimum distance from the center to any bound edge.
+template<typename BoundType,
+         typename StatisticType,
+         typename MatType,
+         typename SplitType>
+inline double BinarySpaceTree<BoundType, StatisticType, MatType, SplitType>::
+    MinimumBoundDistance() const
+{
+  return minimumBoundDistance;
+}
+
 /**
  * Return the specified child.
  */
@@ -560,6 +572,15 @@
   // Calculate the furthest descendant distance.
   furthestDescendantDistance = 0.5 * bound.Diameter();
 
+  // Find the minimum distance to any bound edge.
+  minimumBoundDistance = DBL_MAX;
+  for (size_t i = 0; i < bound.Dim(); ++i)
+  {
+    const double dist = std::max(bound[i].Hi() - bound[i].Lo(), 0.0);
+    if (dist < minimumBoundDistance)
+      minimumBoundDistance = dist;
+  }
+
   // Now, check if we need to split at all.
   if (count <= maxLeafSize)
     return; // We can't split this.
@@ -616,6 +637,15 @@
   // Calculate the furthest descendant distance.
   furthestDescendantDistance = 0.5 * bound.Diameter();
 
+  // Find the minimum distance to any bound edge.
+  minimumBoundDistance = DBL_MAX;
+  for (size_t i = 0; i < bound.Dim(); ++i)
+  {
+    const double dist = std::max(bound[i].Hi() - bound[i].Lo(), 0.0);
+    if (dist < minimumBoundDistance)
+      minimumBoundDistance = dist;
+  }
+
   // First, check if we need to split at all.
   if (count <= maxLeafSize)
     return; // We can't split this.

Modified: mlpack/trunk/src/mlpack/core/tree/cover_tree/cover_tree.hpp
==============================================================================
--- mlpack/trunk/src/mlpack/core/tree/cover_tree/cover_tree.hpp	(original)
+++ mlpack/trunk/src/mlpack/core/tree/cover_tree/cover_tree.hpp	Thu Jul 10 10:02:09 2014
@@ -320,6 +320,10 @@
   //! descendant.
   double& FurthestDescendantDistance() { return furthestDescendantDistance; }
 
+  //! Get the minimum distance from the center to any bound edge (this is the
+  //! same as furthestDescendantDistance).
+  double MinimumBoundDistance() const { return furthestDescendantDistance; }
+
   //! Get the centroid of the node and store it in the given vector.
   void Centroid(arma::vec& centroid) const { centroid = dataset.col(point); }
 

Modified: mlpack/trunk/src/mlpack/core/tree/rectangle_tree/rectangle_tree.hpp
==============================================================================
--- mlpack/trunk/src/mlpack/core/tree/rectangle_tree/rectangle_tree.hpp	(original)
+++ mlpack/trunk/src/mlpack/core/tree/rectangle_tree/rectangle_tree.hpp	Thu Jul 10 10:02:09 2014
@@ -228,7 +228,7 @@
   const std::vector<size_t>& Points() const { return points; }
   //! Modify the points vector for this node.  Be careful!
   std::vector<size_t>& Points() { return points; }
-  
+
   //! Get the local dataset of this node.
   const arma::mat& LocalDataset() const { return *localDataset; }
   //! Modify the local dataset of this node.
@@ -265,6 +265,11 @@
    */
   double FurthestDescendantDistance() const;
 
+  //! Return the minimum distance from the center to any edge of the bound.
+  //! Currently, this returns 0, which doesn't break algorithms, but it isn't
+  //! necessarily correct, either.
+  double MinimumBoundDistance() const { return 0.0; }
+
   //! Return the distance from the center of this node to the center of the
   //! parent node.
   double ParentDistance() const { return parentDistance; }



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