Package org.ejml.dense.row.decompose.hessenberg

Class TridiagonalDecompositionHouseholder_CDRM

java.lang.Object
org.ejml.dense.row.decompose.hessenberg.TridiagonalDecompositionHouseholder_CDRM
All Implemented Interfaces:
org.ejml.interfaces.decomposition.DecompositionInterface<org.ejml.data.CMatrixRMaj>, org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition<org.ejml.data.CMatrixRMaj>, org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition_F32<org.ejml.data.CMatrixRMaj>
@Generated("org.ejml.dense.row.decompose.hessenberg.TridiagonalDecompositionHouseholder_ZDRM")
public class TridiagonalDecompositionHouseholder_CDRM
extends Object
implements org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition_F32<org.ejml.data.CMatrixRMaj>

Performs a complex similar tridiagonal decomposition on a square Hermitian matrix. Householder vectors perform the similar operation and the symmetry is taken advantage of for good performance.

Finds the decomposition of a matrix in the form of:

A = O*T*OH

where A is a Hermitian m by m matrix, O is an orthogonal matrix, and T is a tridiagonal matrix.

This implementation is inspired by description of the real symmetric decomposition in:

David S. Watkins, "Fundamentals of Matrix Computations," Second Edition. Page 349-355

  • Constructor Summary

    Constructors
    Constructor Description
    TridiagonalDecompositionHouseholder_CDRM()  

  • Method Summary

    Modifier and Type Method Description
    boolean decompose​(org.ejml.data.CMatrixRMaj A)
    Decomposes the provided symmetric matrix.
    void getDiagonal​(float[] diag, float[] off)  
    float[] getGammas()  
    org.ejml.data.CMatrixRMaj getQ​(@Nullable org.ejml.data.CMatrixRMaj Q, boolean transposed)
    An orthogonal matrix that has the following property: T = QHAQ
    org.ejml.data.CMatrixRMaj getQT()
    Returns the internal matrix where the decomposed results are stored.
    org.ejml.data.CMatrixRMaj getT​(@Nullable org.ejml.data.CMatrixRMaj T)
    Extracts the tridiagonal matrix found in the decomposition.
    void householderSymmetric​(int row, float gamma)
    Performs the householder operations on left and right and side of the matrix.
    void init​(org.ejml.data.CMatrixRMaj A)
    If needed declares and sets up internal data structures.
    boolean inputModified()  

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • TridiagonalDecompositionHouseholder_CDRM

      public TridiagonalDecompositionHouseholder_CDRM()

  • Method Details

    • getQT

      public org.ejml.data.CMatrixRMaj getQT()
      Returns the internal matrix where the decomposed results are stored.

    • getDiagonal

      public void getDiagonal​(float[] diag, float[] off)
      Specified by:
      getDiagonal in interface org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition_F32<org.ejml.data.CMatrixRMaj>

    • getT

      public org.ejml.data.CMatrixRMaj getT​(@Nullable @Nullable org.ejml.data.CMatrixRMaj T)
      Extracts the tridiagonal matrix found in the decomposition.
      Specified by:
      getT in interface org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition<org.ejml.data.CMatrixRMaj>
      Parameters:
      T - If not null then the results will be stored here. Otherwise a new matrix will be created.
      Returns:
      The extracted T matrix.

    • getQ

      public org.ejml.data.CMatrixRMaj getQ​(@Nullable @Nullable org.ejml.data.CMatrixRMaj Q, boolean transposed)
      An orthogonal matrix that has the following property: T = QHAQ
      Specified by:
      getQ in interface org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition<org.ejml.data.CMatrixRMaj>
      Parameters:
      Q - If not null then the results will be stored here. Otherwise a new matrix will be created.
      Returns:
      The extracted Q matrix.

    • decompose

      public boolean decompose​(org.ejml.data.CMatrixRMaj A)
      Decomposes the provided symmetric matrix.
      Specified by:
      decompose in interface org.ejml.interfaces.decomposition.DecompositionInterface<org.ejml.data.CMatrixRMaj>
      Parameters:
      A - Symmetric matrix that is going to be decomposed. Not modified.

    • householderSymmetric

      public void householderSymmetric​(int row, float gamma)
      Performs the householder operations on left and right and side of the matrix. QTAQ
      Parameters:
      row - Specifies the submatrix.
      gamma - The gamma for the householder operation

    • init

      public void init​(org.ejml.data.CMatrixRMaj A)
      If needed declares and sets up internal data structures.
      Parameters:
      A - Matrix being decomposed.

    • inputModified

      public boolean inputModified()
      Specified by:
      inputModified in interface org.ejml.interfaces.decomposition.DecompositionInterface<org.ejml.data.CMatrixRMaj>

    • getGammas

      public float[] getGammas()