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vnl_sparse_symmetric_eigensystem Class Reference

#include <vnl_sparse_symmetric_eigensystem.h>

List of all members.

Detailed Description

Find the eigenvalues of a sparse symmetric matrix.

Solve the eigenproblem $A x = \lambda x$ , with $A$ symmetric and sparse. The block Lanczos algorithm is used to allow the recovery of a number of eigenvalue/eigenvector pairs from either end of the spectrum, to a required accuracy.

Uses the dnlaso routine from the LASO package of netlib.

Definition at line 29 of file vnl_sparse_symmetric_eigensystem.h.

Public Member Functions

 vnl_sparse_symmetric_eigensystem ()
 ~vnl_sparse_symmetric_eigensystem ()
int CalculateNPairs (vnl_sparse_matrix< double > &M, int n, bool smallest=true, long nfigures=10)
 Here is where the fortran converted code gets called.
vnl_vector< double > get_eigenvector (int i) const
 Return a calculated eigenvector.
double get_eigenvalue (int i) const
int CalculateProduct (int n, int m, const double *p, double *q)
 Callback from solver to calculate the product A p.
int SaveVectors (int n, int m, const double *q, int base)
 Callback to store vectors for dnlaso.
int RestoreVectors (int n, int m, double *q, int base)
 Callback to restore vectors for dnlaso.

Protected Attributes

int nvalues
vnl_vector< double > * vectors
double * values
vnl_sparse_matrix< double > * mat
vcl_vector< double * > temp_store

Constructor & Destructor Documentation

vnl_sparse_symmetric_eigensystem::vnl_sparse_symmetric_eigensystem (   ) 
 

Definition at line 59 of file vnl_sparse_symmetric_eigensystem.cxx.

vnl_sparse_symmetric_eigensystem::~vnl_sparse_symmetric_eigensystem (   ) 
 

Definition at line 64 of file vnl_sparse_symmetric_eigensystem.cxx.

Member Function Documentation

int vnl_sparse_symmetric_eigensystem::CalculateNPairs (  vnl_sparse_matrix< double > &  M,
int  n,
bool  smallest = true,
long  nfigures = 10
) 
 

Here is where the fortran converted code gets called.

The sparse matrix M is assumed to be symmetric. The n smallest eigenvalues and their corresponding eigenvectors are calculated if smallest is true (the default). Otherwise the n largest eigenpairs are found. The accuracy of the eigenvalues is to nfigures decimal digits. Returns 0 if successful, non-zero otherwise.

Definition at line 80 of file vnl_sparse_symmetric_eigensystem.cxx.

int vnl_sparse_symmetric_eigensystem::CalculateProduct (  int  n,
int  m,
const double *  p,
double *  q
) 
 

Callback from solver to calculate the product A p.

Definition at line 206 of file vnl_sparse_symmetric_eigensystem.cxx.

double vnl_sparse_symmetric_eigensystem::get_eigenvalue (  int  i  )  const
 

Definition at line 271 of file vnl_sparse_symmetric_eigensystem.cxx.

vnl_vector< double > vnl_sparse_symmetric_eigensystem::get_eigenvector (  int  i  )  const
 

Return a calculated eigenvector.

Definition at line 265 of file vnl_sparse_symmetric_eigensystem.cxx.

int vnl_sparse_symmetric_eigensystem::RestoreVectors (  int  n,
int  m,
double *  q,
int  base
) 
 

Callback to restore vectors for dnlaso.

Definition at line 243 of file vnl_sparse_symmetric_eigensystem.cxx.

int vnl_sparse_symmetric_eigensystem::SaveVectors (  int  n,
int  m,
const double *  q,
int  base
) 
 

Callback to store vectors for dnlaso.

Definition at line 218 of file vnl_sparse_symmetric_eigensystem.cxx.

Member Data Documentation

vnl_sparse_matrix<double>* vnl_sparse_symmetric_eigensystem::mat [protected]
 

Definition at line 55 of file vnl_sparse_symmetric_eigensystem.h.

int vnl_sparse_symmetric_eigensystem::nvalues [protected]
 

Definition at line 51 of file vnl_sparse_symmetric_eigensystem.h.

vcl_vector<double*> vnl_sparse_symmetric_eigensystem::temp_store [protected]
 

Definition at line 57 of file vnl_sparse_symmetric_eigensystem.h.

double* vnl_sparse_symmetric_eigensystem::values [protected]
 

Definition at line 53 of file vnl_sparse_symmetric_eigensystem.h.

vnl_vector<double>* vnl_sparse_symmetric_eigensystem::vectors [protected]
 

Definition at line 52 of file vnl_sparse_symmetric_eigensystem.h.

The documentation for this class was generated from the following files:
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