mikera.matrixx.decompose.impl.qr

Class HouseholderColQR

java.lang.Object

mikera.matrixx.decompose.impl.qr.HouseholderColQR

All Implemented Interfaces:

QRDecomposition

public class HouseholderColQR
extends java.lang.Object
implements QRDecomposition

Householder QR decomposition is rich in operations along the columns of the matrix. This can be taken advantage of by solving for the Q matrix in a column major format to reduce the number of CPU cache misses and the number of copies that are performed.

Constructor Summary

Constructors

Constructor and Description
HouseholderColQR(boolean compact)

Method Summary

Modifier and Type	Method and Description
QRResult	decompose(AMatrix A) To decompose the matrix 'A' it must have full rank.
double[]	getGammas()
AMatrix	getQ()
double[][]	getQR() Returns the combined QR matrix in a 2D array format that is column major.
AMatrix	getR()

Methods inherited from class java.lang.Object

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

Constructor Detail

HouseholderColQR

public HouseholderColQR(boolean compact)

Method Detail

getQR

public double[][] getQR()

Returns the combined QR matrix in a 2D array format that is column major.

Returns:

The QR matrix in a 2D matrix column major format. [ column ][ row ]

getQ

public AMatrix getQ()

Returns:

The Q matrix from the decomposition.

getR

public AMatrix getR()

Returns:

The R matrix from the decomposition.

decompose

public QRResult decompose(AMatrix A)

To decompose the matrix 'A' it must have full rank. 'A' is a 'm' by 'n' matrix. It requires about 2n*m²-2m²/3 flops.

The matrix provided here can be of different dimension than the one specified in the constructor. It just has to be smaller than or equal to it.

Specified by:

decompose in interface QRDecomposition

getGammas

public double[] getGammas()