cosine_tree.hpp
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1 
12 #ifndef MLPACK_CORE_TREE_COSINE_TREE_COSINE_TREE_HPP
13 #define MLPACK_CORE_TREE_COSINE_TREE_COSINE_TREE_HPP
14 
15 #include <mlpack/prereqs.hpp>
16 #include <boost/heap/priority_queue.hpp>
17 
18 namespace mlpack {
19 namespace tree {
20 
21 // Predeclare classes for CosineNodeQueue typedef.
22 class CompareCosineNode;
23 class CosineTree;
24 
25 // CosineNodeQueue typedef.
26 typedef boost::heap::priority_queue<CosineTree*,
27  boost::heap::compare<CompareCosineNode> > CosineNodeQueue;
28 
29 class CosineTree
30 {
31  public:
40  CosineTree(const arma::mat& dataset);
41 
51  CosineTree(CosineTree& parentNode, const std::vector<size_t>& subIndices);
52 
67  CosineTree(const arma::mat& dataset,
68  const double epsilon,
69  const double delta);
70 
76  CosineTree(const CosineTree& other);
77 
84  CosineTree(CosineTree&& other);
85 
91  CosineTree& operator=(const CosineTree& other);
92 
98  CosineTree& operator=(CosineTree&& other);
99 
103  ~CosineTree();
104 
114  void ModifiedGramSchmidt(CosineNodeQueue& treeQueue,
115  arma::vec& centroid,
116  arma::vec& newBasisVector,
117  arma::vec* addBasisVector = NULL);
118 
131  double MonteCarloError(CosineTree* node,
132  CosineNodeQueue& treeQueue,
133  arma::vec* addBasisVector1 = NULL,
134  arma::vec* addBasisVector2 = NULL);
135 
141  void ConstructBasis(CosineNodeQueue& treeQueue);
142 
148  void CosineNodeSplit();
149 
156  void ColumnSamplesLS(std::vector<size_t>& sampledIndices,
157  arma::vec& probabilities, size_t numSamples);
158 
165  size_t ColumnSampleLS();
166 
179  size_t BinarySearch(arma::vec& cDistribution, double value, size_t start,
180  size_t end);
181 
189  void CalculateCosines(arma::vec& cosines);
190 
195  void CalculateCentroid();
196 
198  void GetFinalBasis(arma::mat& finalBasis) { finalBasis = basis; }
199 
201  const arma::mat& GetDataset() const { return *dataset; }
202 
204  std::vector<size_t>& VectorIndices() { return indices; }
205 
207  void L2Error(const double error) { this->l2Error = error; }
209  double L2Error() const { return l2Error; }
210 
212  arma::vec& Centroid() { return centroid; }
213 
215  void BasisVector(arma::vec& bVector) { this->basisVector = bVector; }
216 
218  arma::vec& BasisVector() { return basisVector; }
219 
221  CosineTree* Parent() const { return parent; }
223  CosineTree*& Parent() { return parent; }
224 
226  CosineTree* Left() const { return left; }
228  CosineTree*& Left() { return left; }
229 
231  CosineTree* Right() const { return right; }
233  CosineTree*& Right() { return right; }
234 
236  size_t NumColumns() const { return numColumns; }
237 
239  double FrobNormSquared() const { return frobNormSquared; }
240 
242  size_t SplitPointIndex() const { return indices[splitPointIndex]; }
243 
244  private:
246  const arma::mat* dataset;
248  double delta;
250  arma::mat basis;
252  CosineTree* parent;
254  CosineTree* left;
256  CosineTree* right;
258  std::vector<size_t> indices;
260  arma::vec l2NormsSquared;
262  arma::vec centroid;
264  arma::vec basisVector;
266  size_t splitPointIndex;
268  size_t numColumns;
270  double l2Error;
272  double frobNormSquared;
274  bool localDataset;
275 };
276 
278 {
279  public:
280  // Comparison function for construction of priority queue.
281  bool operator() (const CosineTree* a, const CosineTree* b) const
282  {
283  return a->L2Error() < b->L2Error();
284  }
285 };
286 
287 } // namespace tree
288 } // namespace mlpack
289 
290 #endif
void ModifiedGramSchmidt(CosineNodeQueue &treeQueue, arma::vec &centroid, arma::vec &newBasisVector, arma::vec *addBasisVector=NULL)
Calculates the orthonormalization of the passed centroid, with respect to the current vector subspace...
double L2Error() const
Get the Monte Carlo error.
arma::vec & Centroid()
Get pointer to the centroid vector.
CosineTree * Left() const
Get pointer to the left child of the node.
void GetFinalBasis(arma::mat &finalBasis)
Returns the basis of the constructed subspace.
strip_type.hpp
Definition: add_to_po.hpp:21
CosineTree *& Left()
Modify the pointer to the left child of the node.
double MonteCarloError(CosineTree *node, CosineNodeQueue &treeQueue, arma::vec *addBasisVector1=NULL, arma::vec *addBasisVector2=NULL)
Estimates the squared error of the projection of the input node&#39;s matrix onto the current vector subs...
void ConstructBasis(CosineNodeQueue &treeQueue)
Constructs the final basis matrix, after the cosine tree construction.
The core includes that mlpack expects; standard C++ includes and Armadillo.
void L2Error(const double error)
Set the Monte Carlo error.
void ColumnSamplesLS(std::vector< size_t > &sampledIndices, arma::vec &probabilities, size_t numSamples)
Sample &#39;numSamples&#39; points from the Length-Squared distribution of the cosine node.
size_t ColumnSampleLS()
Sample a point from the Length-Squared distribution of the cosine node.
CosineTree * Right() const
Get pointer to the right child of the node.
CosineTree * Parent() const
Get pointer to the parent node.
CosineTree(const arma::mat &dataset)
CosineTree constructor for the root node of the tree.
void CosineNodeSplit()
This function splits the cosine node into two children based on the cosines of the columns contained ...
CosineTree *& Right()
Modify the pointer to the left child of the node.
CosineTree *& Parent()
Modify the pointer to the parent node.
std::vector< size_t > & VectorIndices()
Get the indices of columns in the node.
~CosineTree()
Clean up the CosineTree: release allocated memory (including children).
double FrobNormSquared() const
Get the Frobenius norm squared of columns in the node.
CosineTree & operator=(const CosineTree &other)
Copy the given Cosine Tree.
size_t BinarySearch(arma::vec &cDistribution, double value, size_t start, size_t end)
Sample a column based on the cumulative Length-Squared distribution of the cosine node...
size_t NumColumns() const
Get number of columns of input matrix in the node.
void BasisVector(arma::vec &bVector)
Set the basis vector of the node.
size_t SplitPointIndex() const
Get the column index of split point of the node.
const arma::mat & GetDataset() const
Get pointer to the dataset matrix.
void CalculateCentroid()
Calculate centroid of the columns present in the node.
arma::vec & BasisVector()
Get the basis vector of the node.
void CalculateCosines(arma::vec &cosines)
Calculate cosines of the columns present in the node, with respect to the sampled splitting point...
boost::heap::priority_queue< CosineTree *, boost::heap::compare< CompareCosineNode > > CosineNodeQueue
Definition: cosine_tree.hpp:23