no.uib.cipr.matrix

Class TridiagMatrix

java.lang.Object

no.uib.cipr.matrix.AbstractMatrix

no.uib.cipr.matrix.TridiagMatrix

All Implemented Interfaces:

Iterable<MatrixEntry>, Matrix

public class TridiagMatrix
extends AbstractMatrix

Tridiagonal matrix. Stored in three arrays, one of length n for the diagonal, two of length n-1 for the superdiagonal and subdiagonal entries.

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

Constructors

Constructor and Description
TridiagMatrix(int n) Constructor for TridiagMatrix
TridiagMatrix(Matrix A) Constructor for TridiagMatrix
TridiagMatrix(Matrix A, boolean deep) Constructor for TridiagMatrix

Method Summary

Modifier and Type	Method and Description
void	add(int row, int column, double value) A(row,column) += value
TridiagMatrix	copy() Creates a deep copy of the matrix
double	get(int row, int column) Returns A(row,column)
double[]	getDiagonal() Returns the diagonal entries.
double[]	getSubDiagonal() Returns the sub diagonal entries.
double[]	getSuperDiagonal() Returns the super diagonal entries.
Iterator<MatrixEntry>	iterator()
void	set(int row, int column, double value) A(row,column) = value
Matrix	solve(Matrix B, Matrix X) X = A\B.
Vector	solve(Vector b, Vector x) x = A\b.
Matrix	transpose() Transposes the matrix in-place.
TridiagMatrix	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, mult, multAdd, multAdd, multAdd, multAdd, norm, norm1, normF, normInf, numColumns, numRows, rank1, rank1, rank1, rank1, rank1, rank1, rank2, rank2, rank2, rank2, scale, set, set, toString, transABmult, transABmult, transABmultAdd, transABmultAdd, transAmult, transAmult, transAmultAdd, transAmultAdd, transBmult, transBmult, transBmultAdd, transBmultAdd, transMult, transMult, transMultAdd, transMultAdd, transpose, transRank1, transRank1, transRank2, transRank2, transSolve, transSolve

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

TridiagMatrix

public TridiagMatrix(int n)

Constructor for TridiagMatrix

Parameters:

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

TridiagMatrix

public TridiagMatrix(Matrix A)

Constructor for TridiagMatrix

Parameters:

A - Matrix to copy from. Only the tridiagonal part is copied

TridiagMatrix

public TridiagMatrix(Matrix A,
                     boolean deep)

Constructor for TridiagMatrix

Parameters:

A - Matrix to copy from. Only the tridiagonal part is copied

deep - True for a deep copy, else it's shallow. For shallow copies, A must be a TridiagMatrix

Method Detail

getDiagonal

public double[] getDiagonal()

Returns the diagonal entries. Length equal n

getSubDiagonal

public double[] getSubDiagonal()

Returns the sub diagonal entries. Length equal n-1

getSuperDiagonal

public double[] getSuperDiagonal()

Returns the super diagonal entries. Length equal n-1

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

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

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

copy

public TridiagMatrix 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

zero

public TridiagMatrix 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

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

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

iterator

public Iterator<MatrixEntry> iterator()

Specified by:

iterator in interface Iterable<MatrixEntry>

Overrides:

iterator in class AbstractMatrix