org.ejml.alg.dense.decomposition.hessenberg
Class TridiagonalDecompositionHouseholderOrig

java.lang.Object
  org.ejml.alg.dense.decomposition.hessenberg.TridiagonalDecompositionHouseholderOrig

public class TridiagonalDecompositionHouseholderOrig
extends Object

A straight forward implementation from "Fundamentals of Matrix Computations," Second Edition.

This is only saved to provide a point of reference in benchmarks.

Author:

Peter Abeles

Constructor Summary

TridiagonalDecompositionHouseholderOrig()

Method Summary

void	decompose(DenseMatrix64F A) Decomposes the provided symmetric matrix.
double	getGamma(int index)
DenseMatrix64F	getQ(DenseMatrix64F Q) An orthogonal matrix that has the following property: T = QTAQ
DenseMatrix64F	getQT() Returns the interal matrix where the decomposed results are stored.
DenseMatrix64F	getT(DenseMatrix64F T) Extracts the tridiagonal matrix found in the decomposition.
void	householderSymmetric(int row, double gamma) Performs the householder operations on left and right and side of the matrix.
void	init(DenseMatrix64F A) If needed declares and sets up internal data structures.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TridiagonalDecompositionHouseholderOrig

public TridiagonalDecompositionHouseholderOrig()

Method Detail

getQT

public DenseMatrix64F getQT()

Returns the interal matrix where the decomposed results are stored.

Returns:

getT

public DenseMatrix64F getT(DenseMatrix64F T)

Extracts the tridiagonal matrix found in the decomposition.

Parameters:

T - If not null then the results will be stored here. Otherwise a new matrix will be created.

Returns:

The extracted T matrix.

getQ

public DenseMatrix64F getQ(DenseMatrix64F Q)

An orthogonal matrix that has the following property: T = Q^TAQ

Parameters:

Q - If not null then the results will be stored here. Otherwise a new matrix will be created.

Returns:

The extracted Q matrix.

decompose

public void decompose(DenseMatrix64F A)

Decomposes the provided symmetric matrix.

Parameters:

A - Symmetric matrix that is going to be decomposed. Not modified.

householderSymmetric

public void householderSymmetric(int row,
                                 double gamma)

Performs the householder operations on left and right and side of the matrix. Q^TAQ

Parameters:

row - Specifies the submatrix.

gamma - The gamma for the householder operation

init

public void init(DenseMatrix64F A)

If needed declares and sets up internal data structures.

Parameters:

A - Matrix being decomposed.

getGamma

public double getGamma(int index)