Package org.ejml.dense.row.decomposition.bidiagonal

Class BidiagonalDecompositionRow_DDRM

java.lang.Object
org.ejml.dense.row.decomposition.bidiagonal.BidiagonalDecompositionRow_DDRM
All Implemented Interfaces:
BidiagonalDecomposition<DMatrixRMaj>, BidiagonalDecomposition_F64<DMatrixRMaj>, DecompositionInterface<DMatrixRMaj>
Direct Known Subclasses:
BidiagonalDecompositionRow_MT_DDRM
public class BidiagonalDecompositionRow_DDRM extends Object implements BidiagonalDecomposition_F64<DMatrixRMaj>

Performs a BidiagonalDecomposition_F64 using householder reflectors. This is efficient on wide or square matrices.

  • Field Details

    • b

      protected double[] b

    • u

      protected double[] u

  • Constructor Details

    • BidiagonalDecompositionRow_DDRM

      public BidiagonalDecompositionRow_DDRM(int numElements)
      Creates a decompose that defines the specified amount of memory.
      Parameters:
      numElements - number of elements in the matrix.

    • BidiagonalDecompositionRow_DDRM

      public BidiagonalDecompositionRow_DDRM()

  • Method Details

    • decompose

      public boolean decompose(DMatrixRMaj A)
      Computes the decomposition of the provided matrix. If no errors are detected then true is returned, false otherwise.
      Specified by:
      decompose in interface DecompositionInterface<DMatrixRMaj>
      Parameters:
      A - The matrix that is being decomposed. Not modified.
      Returns:
      If it detects any errors or not.

    • init

      protected void init(DMatrixRMaj A)
      Sets up internal data structures and creates a copy of the input matrix.
      Parameters:
      A - The input matrix. Not modified.

    • getUBV

      public DMatrixRMaj getUBV()
      The raw UBV matrix that is stored internally.
      Returns:
      UBV matrix.

    • getDiagonal

      public void getDiagonal(double[] diag, double[] off)
      Description copied from interface: BidiagonalDecomposition_F64
      Extracts the diagonal and off diagonal elements from the decomposition.
      Specified by:
      getDiagonal in interface BidiagonalDecomposition_F64<DMatrixRMaj>
      Parameters:
      diag - diagonal elements from B.
      off - off diagonal elements form B.

    • getB

      public DMatrixRMaj getB(@Nullable @Nullable DMatrixRMaj B, boolean compact)
      Returns the bidiagonal matrix.
      Specified by:
      getB in interface BidiagonalDecomposition<DMatrixRMaj>
      Parameters:
      B - If not null the results are stored here, if null a new matrix is created.
      Returns:
      The bidiagonal matrix.

    • handleB

      public static DMatrixRMaj handleB(@Nullable @Nullable DMatrixRMaj B, boolean compact, int m, int n, int min)

    • getU

      public DMatrixRMaj getU(@Nullable @Nullable DMatrixRMaj U, boolean transpose, boolean compact)
      Returns the orthogonal U matrix.
      Specified by:
      getU in interface BidiagonalDecomposition<DMatrixRMaj>
      Parameters:
      U - If not null then the results will be stored here. Otherwise a new matrix will be created.
      Returns:
      The extracted Q matrix.

    • handleU

      public static DMatrixRMaj handleU(@Nullable @Nullable DMatrixRMaj U, boolean transpose, boolean compact, int m, int n, int min)

    • getV

      public DMatrixRMaj getV(@Nullable @Nullable DMatrixRMaj V, boolean transpose, boolean compact)
      Returns the orthogonal V matrix.
      Specified by:
      getV in interface BidiagonalDecomposition<DMatrixRMaj>
      Parameters:
      V - If not null then the results will be stored here. Otherwise a new matrix will be created.
      Returns:
      The extracted Q matrix.

    • handleV

      public static DMatrixRMaj handleV(@Nullable @Nullable DMatrixRMaj V, boolean transpose, boolean compact, int m, int n, int min)

    • computeU

      protected void computeU(int k)

    • rank1UpdateMultL

      protected void rank1UpdateMultL(DMatrixRMaj A, double gamma, int colA0, int w0, int w1)

    • rank1UpdateMultR

      protected void rank1UpdateMultR(DMatrixRMaj A, double gamma, int colA0, int w0, int w1)

    • computeV

      protected void computeV(int k)

    • getGammasU

      public double[] getGammasU()
      Returns gammas from the householder operations for the U matrix.

    • getGammasV

      public double[] getGammasV()
      Returns gammas from the householder operations for the V matrix.

    • inputModified

      public boolean inputModified()
      Description copied from interface: DecompositionInterface
      Checks if the input matrix to DecompositionInterface.decompose(org.ejml.data.Matrix) is modified during the decomposition process.
      Specified by:
      inputModified in interface DecompositionInterface<DMatrixRMaj>
      Returns:
      true if the input matrix to decompose() is modified.