Package org.flag4j.linalg.decompositions.qr

Class ComplexQR

java.lang.Object

org.flag4j.linalg.decompositions.unitary.UnitaryDecomposition<CMatrix,CNumber[]>

org.flag4j.linalg.decompositions.unitary.ComplexUnitaryDecomposition

org.flag4j.linalg.decompositions.qr.ComplexQR

All Implemented Interfaces:

Decomposition<CMatrix>

public class ComplexQR
extends ComplexUnitaryDecomposition

Instances of this class compute the QR decomposition of a complex dense matrix.

The QR decomposition, decomposes a matrix A into a unitary matrix Q and an upper triangular matrix R such that A=QR.

Much of this code has been adapted from the EJML library.

Field Summary

Fields

Modifier and Type	Field	Description
protected final boolean	reduced	Flag indicating if the reduced (true) or full (false) QR decomposition should be computed.

Fields inherited from class org.flag4j.linalg.decompositions.unitary.ComplexUnitaryDecomposition

norm, normRe

Fields inherited from class org.flag4j.linalg.decompositions.unitary.UnitaryDecomposition

applyUpdate, householderVector, minAxisSize, numCols, numRows, qFactors, storeReflectors, subDiagonal, transformData, transformMatrix, workArray

Constructor Summary

Constructors

Constructor	Description
ComplexQR()	Creates a QR decomposer.
ComplexQR(boolean reduced)	Creates a QR decomposer to compute either the full or reduced QR decomposition.

Method Summary

Modifier and Type	Method	Description
ComplexQR	decompose(CMatrix src)	Computes the QR decomposition of a real dense matrix.
CMatrix	getR()	Gets the upper triangular matrix R from the QR decomposition.
CMatrix	getUpper()	Gets the upper triangular matrix R from the last decomposition.
protected CMatrix	initQ()	Creates and initializes Q to the appropriately sized identity matrix.

Methods inherited from class org.flag4j.linalg.decompositions.unitary.ComplexUnitaryDecomposition

computeHouseholder, computePhasedNorm, findMaxAndInit, getQ, getUpper, initWorkArrays, updateData

Methods inherited from class org.flag4j.linalg.decompositions.unitary.UnitaryDecomposition

decomposeBase, setUp

Methods inherited from class java.lang.Object

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

Field Details

reduced

protected final boolean reduced

Flag indicating if the reduced (true) or full (false) QR decomposition should be computed.

Constructor Details

ComplexQR

public ComplexQR()

Creates a QR decomposer. This decomposer will compute the reduced QR decomposition.

See Also:

• ComplexQR(boolean)

ComplexQR

public ComplexQR(boolean reduced)

Creates a QR decomposer to compute either the full or reduced QR decomposition.

Parameters:

reduced - Flag indicating if this decomposer should compute the full or reduced QR decomposition.

Method Details

decompose

public ComplexQR decompose(CMatrix src)

Computes the QR decomposition of a real dense matrix.

Parameters:

src - The source matrix to decompose.

Returns:

A reference to this decomposer.

initQ

protected CMatrix initQ()

Creates and initializes Q to the appropriately sized identity matrix.

Specified by:

initQ in class UnitaryDecomposition<CMatrix,CNumber[]>

Returns:

An identity matrix with the appropriate size.

getUpper

public CMatrix getUpper()

Gets the upper triangular matrix R from the last decomposition.

Specified by:

getUpper in class UnitaryDecomposition<CMatrix,CNumber[]>

Returns:

The upper triangular matrix R from the last decomposition.

getR

public CMatrix getR()

Gets the upper triangular matrix R from the QR decomposition.

Returns:

The upper triangular matrix R from the QR decomposition.