org.apache.commons.math.linear
Interface QRDecomposition

All Known Implementing Classes:
QRDecompositionImpl

public interface QRDecomposition

An interface to classes that implement an algorithm to calculate the QR-decomposition of a real matrix.

This interface is based on the class with similar name from the JAMA library, with the following changes:

Since:
1.2
Version:
$Revision: 826627 $ $Date: 2009-10-19 12:27:47 +0200 (lun. 19 oct. 2009) $
See Also:
MathWorld, Wikipedia

Method Summary
 RealMatrix getH()
          Returns the Householder reflector vectors.
 RealMatrix getQ()
          Returns the matrix Q of the decomposition.
 RealMatrix getQT()
          Returns the transpose of the matrix Q of the decomposition.
 RealMatrix getR()
          Returns the matrix R of the decomposition.
 DecompositionSolver getSolver()
          Get a solver for finding the A × X = B solution in least square sense.
 

Method Detail

getR

RealMatrix getR()
Returns the matrix R of the decomposition.

R is an upper-triangular matrix

Returns:
the R matrix

getQ

RealMatrix getQ()
Returns the matrix Q of the decomposition.

Q is an orthogonal matrix

Returns:
the Q matrix

getQT

RealMatrix getQT()
Returns the transpose of the matrix Q of the decomposition.

Q is an orthogonal matrix

Returns:
the Q matrix

getH

RealMatrix getH()
Returns the Householder reflector vectors.

H is a lower trapezoidal matrix whose columns represent each successive Householder reflector vector. This matrix is used to compute Q.

Returns:
a matrix containing the Householder reflector vectors

getSolver

DecompositionSolver getSolver()
Get a solver for finding the A × X = B solution in least square sense.

Returns:
a solver


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