Package org.ejml.dense.row.decomposition.lu

Class LUDecompositionBase_DDRM

java.lang.Object
org.ejml.dense.row.decomposition.lu.LUDecompositionBase_DDRM
All Implemented Interfaces:
DecompositionInterface<DMatrixRMaj>, LUDecomposition<DMatrixRMaj>, LUDecomposition_F64<DMatrixRMaj>
Direct Known Subclasses:
LUDecompositionAlt_DDRM
public abstract class LUDecompositionBase_DDRM extends Object implements LUDecomposition_F64<DMatrixRMaj>

Contains common data structures and operations for LU decomposition algorithms.

  • Field Details

    • LU

      protected DMatrixRMaj LU

    • maxWidth

      protected int maxWidth

    • m

      protected int m

    • n

      protected int n

    • dataLU

      protected double[] dataLU

    • vv

      protected double[] vv

    • indx

      protected int[] indx

    • pivot

      protected int[] pivot

    • pivsign

      protected double pivsign

  • Constructor Details

    • LUDecompositionBase_DDRM

      public LUDecompositionBase_DDRM()

  • Method Details

    • setExpectedMaxSize

      public void setExpectedMaxSize(int numRows, int numCols)

    • getLU

      public DMatrixRMaj getLU()

    • getIndx

      public int[] getIndx()

    • getPivot

      public int[] getPivot()

    • 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.

    • getLower

      public DMatrixRMaj getLower(@Nullable @Nullable DMatrixRMaj lower)
      Writes the lower triangular matrix into the specified matrix.
      Specified by:
      getLower in interface LUDecomposition<DMatrixRMaj>
      Parameters:
      lower - Where the lower triangular matrix is written to.
      Returns:
      The L matrix.

    • getUpper

      public DMatrixRMaj getUpper(@Nullable @Nullable DMatrixRMaj upper)
      Writes the upper triangular matrix into the specified matrix.
      Specified by:
      getUpper in interface LUDecomposition<DMatrixRMaj>
      Parameters:
      upper - Where the upper triangular matrix is writen to.
      Returns:
      The U matrix.

    • getRowPivot

      public DMatrixRMaj getRowPivot(@Nullable @Nullable DMatrixRMaj pivot)
      Description copied from interface: LUDecomposition

      For numerical stability there are often row interchanges. This computes a pivot matrix that will undo those changes.

      Specified by:
      getRowPivot in interface LUDecomposition<DMatrixRMaj>
      Parameters:
      pivot - Storage for the pivot matrix. If null then a new matrix is returned. Modified.
      Returns:
      The pivot matrix.

    • getRowPivotV

      public int[] getRowPivotV(@Nullable @Nullable IGrowArray pivot)
      Description copied from interface: LUDecomposition
      Returns the row pivot vector
      Specified by:
      getRowPivotV in interface LUDecomposition<DMatrixRMaj>
      Parameters:
      pivot - (Optional) Storage for pivot vector
      Returns:
      The pivot vector

    • decomposeCommonInit

      protected void decomposeCommonInit(DMatrixRMaj a)

    • isSingular

      public boolean isSingular()
      Determines if the decomposed matrix is singular. This function can return false and the matrix be almost singular, which is still bad.
      Specified by:
      isSingular in interface LUDecomposition<DMatrixRMaj>
      Returns:
      true if singular false otherwise.

    • computeDeterminant

      public Complex_F64 computeDeterminant()
      Computes the determinant from the LU decomposition.
      Specified by:
      computeDeterminant in interface LUDecomposition_F64<DMatrixRMaj>
      Returns:
      The matrix's determinant.

    • quality

      public double quality()

    • _solveVectorInternal

      public void _solveVectorInternal(double[] vv)
      a specialized version of solve that avoid additional checks that are not needed.

    • _getVV

      public double[] _getVV()