no.uib.cipr.matrix
Class LowerTriangPackMatrix

java.lang.Object
  no.uib.cipr.matrix.AbstractMatrix
      no.uib.cipr.matrix.LowerTriangPackMatrix

All Implemented Interfaces:

java.lang.Iterable<MatrixEntry>, Matrix

Direct Known Subclasses:

UnitLowerTriangPackMatrix

public class LowerTriangPackMatrix
extends AbstractMatrix

Lower triangular packed matrix. In contrast with LowerTriangDenseMatrix, this matrix exploits the sparsity by only storing about half the matrix. As such, the triangular matrix

a11
a21	a22
a31	a32	a33
a41	a42	a43	a44

is packed as follows:

a11

a21

a31

a41

a22

a32

a42

a33

a43

a44

Nested Class Summary

Nested classes/interfaces inherited from interface no.uib.cipr.matrix.Matrix

Matrix.Norm

Field Summary

Fields inherited from class no.uib.cipr.matrix.AbstractMatrix

numColumns, numRows

Constructor Summary

LowerTriangPackMatrix(int n)
Constructor for LowerTriangPackMatrix

LowerTriangPackMatrix(Matrix A)
Constructor for LowerTriangPackMatrix

LowerTriangPackMatrix(Matrix A, boolean deep)
Constructor for LowerTriangPackMatrix

Method Summary

void	add(int row, int column, double value) A(row,column) += value
LowerTriangPackMatrix	copy() Creates a deep copy of the matrix
double	get(int row, int column) Returns A(row,column)
double[]	getData() Returns the matrix contents.
java.util.Iterator<MatrixEntry>	iterator()
Vector	mult(double alpha, Vector x, Vector y) y = alpha*A*x
void	set(int row, int column, double value) A(row,column) = value
Matrix	set(Matrix B) A=B.
Matrix	solve(Matrix B, Matrix X) X = A\B.
Vector	solve(Vector b, Vector x) x = A\b.
Vector	transMult(double alpha, Vector x, Vector y) y = alpha*AT*x
Matrix	transSolve(Matrix B, Matrix X) X = AT\B.
Vector	transSolve(Vector b, Vector x) x = AT\b.
Matrix	zero() Zeros all the entries in the matrix, while preserving any underlying structure.

Methods inherited from class no.uib.cipr.matrix.AbstractMatrix

add, add, check, checkMultAdd, checkMultAdd, checkRank1, checkRank1, checkRank2, checkRank2, checkSize, checkSolve, checkSolve, checkTransABmultAdd, checkTransAmultAdd, checkTransBmultAdd, checkTransMultAdd, checkTranspose, checkTranspose, checkTransRank1, checkTransRank2, isSquare, max, max, mult, mult, mult, multAdd, multAdd, multAdd, multAdd, norm, norm1, normF, normInf, numColumns, numRows, rank1, rank1, rank1, rank1, rank1, rank1, rank2, rank2, rank2, rank2, scale, set, toString, transABmult, transABmult, transABmultAdd, transABmultAdd, transAmult, transAmult, transAmultAdd, transAmultAdd, transBmult, transBmult, transBmultAdd, transBmultAdd, transMult, transMultAdd, transMultAdd, transpose, transpose, transRank1, transRank1, transRank2, transRank2

Methods inherited from class java.lang.Object

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

Constructor Detail

LowerTriangPackMatrix

public LowerTriangPackMatrix(int n)

Constructor for LowerTriangPackMatrix

Parameters:

n - Size of the matrix. Since the matrix must be square, this equals both the number of rows and columns

LowerTriangPackMatrix

public LowerTriangPackMatrix(Matrix A)

Constructor for LowerTriangPackMatrix

Parameters:

A - Matrix to copy contents from. Only the entries of the relevant part are copied

LowerTriangPackMatrix

public LowerTriangPackMatrix(Matrix A,
                             boolean deep)

Constructor for LowerTriangPackMatrix

Parameters:

A - Matrix to copy contents from. Only the entries of the relevant part are copied

deep - True if the copy is deep, else false (giving a shallow copy). For shallow copies, A must be a packed matrix

Method Detail

add

public void add(int row,
                int column,
                double value)

Description copied from interface: Matrix

A(row,column) += value

Specified by:

add in interface Matrix

Overrides:

add in class AbstractMatrix

set

public void set(int row,
                int column,
                double value)

Description copied from interface: Matrix

A(row,column) = value

Specified by:

set in interface Matrix

Overrides:

set in class AbstractMatrix

get

public double get(int row,
                  int column)

Description copied from interface: Matrix

Returns A(row,column)

Specified by:

get in interface Matrix

Overrides:

get in class AbstractMatrix

copy

public LowerTriangPackMatrix copy()

Description copied from interface: Matrix

Creates a deep copy of the matrix

Specified by:

copy in interface Matrix

Overrides:

copy in class AbstractMatrix

Returns:

A

mult

public Vector mult(double alpha,
                   Vector x,
                   Vector y)

Description copied from interface: Matrix

y = alpha*A*x

Specified by:

mult in interface Matrix

Overrides:

mult in class AbstractMatrix

x - Vector of size A.numColumns()

y - Vector of size A.numRows()

Returns:

y

transMult

public Vector transMult(double alpha,
                        Vector x,
                        Vector y)

Description copied from interface: Matrix

y = alpha*AT*x

Specified by:

transMult in interface Matrix

Overrides:

transMult in class AbstractMatrix

x - Vector of size A.numRows()

y - Vector of size A.numColumns()

Returns:

y

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

Overrides:

solve in class AbstractMatrix

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

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

iterator

public java.util.Iterator<MatrixEntry> iterator()

Specified by:

iterator in interface java.lang.Iterable<MatrixEntry>

Overrides:

iterator in class AbstractMatrix

getData

public double[] getData()

Returns the matrix contents. Ordering depends on the underlying storage assumptions

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