Package org.ejml.dense.row.decomposition.hessenberg

Class TridiagonalDecompositionHouseholderOrig_DDRM

java.lang.Object

org.ejml.dense.row.decomposition.hessenberg.TridiagonalDecompositionHouseholderOrig_DDRM

public class TridiagonalDecompositionHouseholderOrig_DDRM
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.

Constructor Summary

Constructors

Constructor	Description
TridiagonalDecompositionHouseholderOrig_DDRM()

Method Summary

Modifier and Type	Method	Description
void	decompose(DMatrixRMaj A)	Decomposes the provided symmetric matrix.
double	getGamma(int index)
DMatrixRMaj	getQ(@Nullable DMatrixRMaj Q)	An orthogonal matrix that has the following property: T = QTAQ
DMatrixRMaj	getQT()	Returns the interal matrix where the decomposed results are stored.
DMatrixRMaj	getT(@Nullable DMatrixRMaj 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(DMatrixRMaj 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 Details

TridiagonalDecompositionHouseholderOrig_DDRM

public TridiagonalDecompositionHouseholderOrig_DDRM()

Method Details

getQT

public DMatrixRMaj getQT()

Returns the interal matrix where the decomposed results are stored.

getT

public DMatrixRMaj getT(@Nullable
 @Nullable DMatrixRMaj 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 DMatrixRMaj getQ(@Nullable
 @Nullable DMatrixRMaj 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(DMatrixRMaj 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(DMatrixRMaj A)

If needed declares and sets up internal data structures.

Parameters:

A - Matrix being decomposed.

getGamma

public double getGamma(int index)