Package org.ejml.dense.row.linsol.qr

Class LinearSolverQrHouseCol_DDRM

java.lang.Object

org.ejml.dense.row.linsol.LinearSolverAbstract_DDRM

org.ejml.dense.row.linsol.qr.LinearSolverQrHouseCol_DDRM

All Implemented Interfaces:

org.ejml.interfaces.linsol.LinearSolver<org.ejml.data.DMatrixRMaj,org.ejml.data.DMatrixRMaj>, org.ejml.interfaces.linsol.LinearSolverDense<org.ejml.data.DMatrixRMaj>

Direct Known Subclasses:

LinearSolverQrHouseCol_MT_DDRM

public class LinearSolverQrHouseCol_DDRM
extends LinearSolverAbstract_DDRM

QR decomposition can be used to solve for systems. However, this is not as computationally efficient as LU decomposition and costs about 3n² flops.

It solve for x by first multiplying b by the transpose of Q then solving for the result.
QRx=b
Rx=Q^T b

A column major decomposition is used in this solver.

Field Summary

Fields

Modifier and Type	Field	Description
protected org.ejml.data.DMatrixRMaj	a
protected QRDecompositionHouseholderColumn_DDRM	decomposer
protected double[]	gammas
protected int	maxCols
protected int	maxRows
protected double[][]	QR
protected org.ejml.data.DMatrixRMaj	R
protected org.ejml.data.DMatrixRMaj	temp

Fields inherited from class org.ejml.dense.row.linsol.LinearSolverAbstract_DDRM

A, numCols, numRows

Constructor Summary

Constructors

Modifier	Constructor	Description
	LinearSolverQrHouseCol_DDRM()	Creates a linear solver that uses QR decomposition.
protected	LinearSolverQrHouseCol_DDRM(QRDecompositionHouseholderColumn_DDRM decomposer)

Method Summary

Modifier and Type	Method	Description
org.ejml.interfaces.decomposition.QRDecomposition<org.ejml.data.DMatrixRMaj>	getDecomposition()
boolean	modifiesA()
boolean	modifiesB()
double	quality()
boolean	setA(org.ejml.data.DMatrixRMaj A)	Performs QR decomposition on A
void	setMaxSize(int maxRows, int maxCols)
void	solve(org.ejml.data.DMatrixRMaj B, org.ejml.data.DMatrixRMaj X)	Solves for X using the QR decomposition.

Methods inherited from class org.ejml.dense.row.linsol.LinearSolverAbstract_DDRM

_setA, getA, invert

Methods inherited from class java.lang.Object

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

Field Details

decomposer

protected final QRDecompositionHouseholderColumn_DDRM decomposer

a

protected final org.ejml.data.DMatrixRMaj a

temp

protected final org.ejml.data.DMatrixRMaj temp

maxRows

protected int maxRows

maxCols

protected int maxCols

QR

protected double[][] QR

R

protected final org.ejml.data.DMatrixRMaj R

gammas

protected double[] gammas

Constructor Details

LinearSolverQrHouseCol_DDRM

public LinearSolverQrHouseCol_DDRM()

Creates a linear solver that uses QR decomposition.

LinearSolverQrHouseCol_DDRM

protected LinearSolverQrHouseCol_DDRM(QRDecompositionHouseholderColumn_DDRM decomposer)

Method Details

setMaxSize

public void setMaxSize(int maxRows,
int maxCols)

setA

public boolean setA(org.ejml.data.DMatrixRMaj A)

Performs QR decomposition on A

Parameters:

A - not modified.

quality

public double quality()

solve

public void solve(org.ejml.data.DMatrixRMaj B,
org.ejml.data.DMatrixRMaj X)

Solves for X using the QR decomposition.

Parameters:

B - A matrix that is n by m. Not modified.

X - An n by m matrix where the solution is written to. Modified.

modifiesA

public boolean modifiesA()

modifiesB

public boolean modifiesB()

getDecomposition

public org.ejml.interfaces.decomposition.QRDecomposition<org.ejml.data.DMatrixRMaj> getDecomposition()