org.apache.mahout.math

Class OldQRDecomposition

java.lang.Object

org.apache.mahout.math.OldQRDecomposition

All Implemented Interfaces:

QR

public class OldQRDecomposition
extends Object
implements QR

partially deprecated until unit tests are in place. Until this time, this class/interface is unsupported.

Constructor Summary

Constructors

Constructor and Description
OldQRDecomposition(Matrix a) Constructs and returns a new QR decomposition object; computed by Householder reflections; The decomposed matrices can be retrieved via instance methods of the returned decomposition object.

Method Summary

Methods

Modifier and Type	Method and Description
Matrix	getQ() Generates and returns the (economy-sized) orthogonal factor Q.
Matrix	getR() Returns the upper triangular factor, R.
boolean	hasFullRank() Returns whether the matrix A has full rank.
Matrix	solve(Matrix B) Least squares solution of A*X = B; returns X.
String	toString() Returns a rough string rendition of a QR.

Methods inherited from class java.lang.Object

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

Constructor Detail

OldQRDecomposition

public OldQRDecomposition(Matrix a)

Constructs and returns a new QR decomposition object; computed by Householder reflections; The decomposed matrices can be retrieved via instance methods of the returned decomposition object.

Parameters:

a - A rectangular matrix.

Throws:

IllegalArgumentException - if A.rows() < A.columns().

Method Detail

getQ

public Matrix getQ()

Generates and returns the (economy-sized) orthogonal factor Q.

Specified by:

getQ in interface QR

Returns:

Q

getR

public Matrix getR()

Returns the upper triangular factor, R.

Specified by:

getR in interface QR

Returns:

R

hasFullRank

public boolean hasFullRank()

Returns whether the matrix A has full rank.

Specified by:

hasFullRank in interface QR

Returns:

true if R, and hence A, has full rank.

solve

public Matrix solve(Matrix B)

Least squares solution of A*X = B; returns X.

Specified by:

solve in interface QR

Parameters:

B - A matrix with as many rows as A and any number of columns.

Returns:

X that minimizes the two norm of Q*R*X - B.

Throws:

IllegalArgumentException - if B.rows() != A.rows().

toString

public String toString()

Returns a rough string rendition of a QR.

Overrides:

toString in class Object