Package no.uib.cipr.matrix

Class LowerSPDBandMatrix

java.lang.Object
no.uib.cipr.matrix.AbstractMatrix
no.uib.cipr.matrix.LowerSymmBandMatrix
no.uib.cipr.matrix.LowerSPDBandMatrix
All Implemented Interfaces:
Iterable<MatrixEntry>, Matrix
public class LowerSPDBandMatrix extends LowerSymmBandMatrix
Lower symmetrical positive definite banded matrix. It does not enforce this property (except for symmetry), and has the same storage layout as LowerSymmBandMatrix.

  • Constructor Details

    • LowerSPDBandMatrix

      public LowerSPDBandMatrix(int n, int kd)
      Constructor for LowerSPDBandMatrix
      Parameters:
      n - Size of the matrix. Since the matrix must be square, this equals both the number of rows and columns
      kd - Number of bands off the main diagonal (off diagonals)

    • LowerSPDBandMatrix

      public LowerSPDBandMatrix(Matrix A, int kd)
      Constructor for LowerSPDBandMatrix
      Parameters:
      A - Matrix to copy contents from. Only the parts of A that lie within the allocated band are copied over, the rest is ignored
      kd - Number of bands off the main diagonal (off diagonals)

    • LowerSPDBandMatrix

      public LowerSPDBandMatrix(Matrix A, int kd, boolean deep)
      Constructor for LowerSPDBandMatrix
      Parameters:
      A - Matrix to copy contents from. Only the parts of A that lie within the allocated band are copied over, the rest is ignored
      kd - Number of bands off the main diagonal (off diagonals)
      deep - True for a deep copy. For shallow copies, A must be a banded matrix

  • Method Details

    • copy

      public LowerSPDBandMatrix copy()
      Description copied from interface: Matrix
      Creates a deep copy of the matrix
      Specified by:
      copy in interface Matrix
      Overrides:
      copy in class LowerSymmBandMatrix
      Returns:
      A

    • solve

      public Matrix solve(Matrix B, Matrix X)
      Description copied from interface: Matrix
      X = A\B. Not all matrices support this operation, those that do not throw UnsupportedOperationException. Note that it is often more efficient to use a matrix decomposition and its associated solver
      Specified by:
      solve in interface Matrix
      Parameters:
      B - Matrix with the same number of rows as A, and the same number of columns as X
      X - Matrix with a number of rows equal A.numColumns(), and the same number of columns as B
      Returns:
      X

    • multAdd

      public Vector multAdd(double alpha, Vector x, Vector y)
      Description copied from interface: Matrix
      y = alpha*A*x + y
      Specified by:
      multAdd in interface Matrix
      Overrides:
      multAdd in class AbstractMatrix
      Parameters:
      x - Vector of size A.numColumns()
      y - Vector of size A.numRows()
      Returns:
      y

    • transMultAdd

      public Vector transMultAdd(double alpha, Vector x, Vector y)
      Description copied from interface: Matrix
      y = alpha*AT*x + y
      Specified by:
      transMultAdd in interface Matrix
      Overrides:
      transMultAdd in class AbstractMatrix
      Parameters:
      x - Vector of size A.numRows()
      y - Vector of size A.numColumns()
      Returns:
      y

    • iterator

      public Iterator<MatrixEntry> iterator()
      Specified by:
      iterator in interface Iterable<MatrixEntry>

    • solve

      public Vector solve(Vector b, Vector x)
      Description copied from interface: Matrix
      x = A\b. Not all matrices support this operation, those that do not throw UnsupportedOperationException. Note that it is often more efficient to use a matrix decomposition and its associated solver
      Specified by:
      solve in interface Matrix
      Overrides:
      solve in class AbstractMatrix
      Parameters:
      b - Vector of size A.numRows()
      x - Vector of size A.numColumns()
      Returns:
      x

    • transSolve

      public Matrix transSolve(Matrix B, Matrix X)
      Description copied from interface: Matrix
      X = AT\B. Not all matrices support this operation, those that do not throw UnsupportedOperationException. Note that it is often more efficient to use a matrix decomposition and its associated transpose solver
      Specified by:
      transSolve in interface Matrix
      Overrides:
      transSolve in class AbstractMatrix
      Parameters:
      B - Matrix with a number of rows equal A.numColumns(), and the same number of columns as X
      X - Matrix with the same number of rows as A, and the same number of columns as B
      Returns:
      X

    • transSolve

      public Vector transSolve(Vector b, Vector x)
      Description copied from interface: Matrix
      x = AT\b. Not all matrices support this operation, those that do not throw UnsupportedOperationException. Note that it is often more efficient to use a matrix decomposition and its associated solver
      Specified by:
      transSolve in interface Matrix
      Overrides:
      transSolve in class AbstractMatrix
      Parameters:
      b - Vector of size A.numColumns()
      x - Vector of size A.numRows()
      Returns:
      x

    • transpose

      public Matrix transpose()
      Description copied from interface: Matrix
      Transposes the matrix in-place. In most cases, the matrix must be square for this to work.
      Specified by:
      transpose in interface Matrix
      Overrides:
      transpose in class AbstractMatrix
      Returns:
      This matrix

    • getData

      public double[] getData()
      Returns the matrix contents

    • numSubDiagonals

      public int numSubDiagonals()
      Returns the number of lower diagonals

    • numSuperDiagonals

      public int numSuperDiagonals()
      Returns the number of upper diagonals

    • set

      public Matrix set(Matrix B)
      Description copied from interface: Matrix
      A=B. The matrices must be of the same size
      Specified by:
      set in interface Matrix
      Overrides:
      set in class AbstractMatrix
      Returns:
      A

    • zero

      public Matrix zero()
      Description copied from interface: Matrix
      Zeros all the entries in the matrix, while preserving any underlying structure. Useful for general, unstructured matrices.
      Specified by:
      zero in interface Matrix
      Overrides:
      zero in class AbstractMatrix
      Returns:
      A