java.lang.Object
- no.uib.cipr.matrix.AbstractMatrix
- - no.uib.cipr.matrix.BandMatrix

All Implemented Interfaces:

java.lang.Iterable<MatrixEntry>, Matrix
```
public class BandMatrix
extends AbstractMatrix
```
Banded matrix. The banded matrix is a useful sparse structure for many kinds of direct computations, however it should only be used if the band is sufficiently narrow as wide bands actually wastes both memory and compute time. The matrix

a₁₁ a₁₂

a₂₁ a₂₂ a₂₃

a₃₁ a₃₂ a₃₃ a₃₄

a₄₂ a₄₃ a₄₄ a₄₅

a₅₃ a₅₄ a₅₅

has two lower diagonals and one upper diagonal. It will be stored in the array

a₁₁ a₂₁ a₃₁ a₂₁ a₂₂ a₃₂ a₄₂ a₂₃ a₃₃ a₄₃ a₅₃ a₃₄ a₄₄ a₅₄ a₄₅ a₅₅

Empty cells are allocated, but never referenced.

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	Description
`BandMatrix(int n, int kl, int ku)`	Constructor for BandMatrix
`BandMatrix(Matrix A, int kl, int ku)`	Constructor for BandMatrix
`BandMatrix(Matrix A, int kl, int ku, boolean deep)`	Constructor for BandMatrix

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`add(int row, int column, double value)`	`A(row,column) += value`
`BandMatrix`	`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`	`multAdd(double alpha, Vector x, Vector y)`	`y = alphaAx + y`
`int`	`numSubDiagonals()`	Returns the number of lower diagonals
`int`	`numSuperDiagonals()`	Returns the number of upper diagonals
`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`	`transMultAdd(double alpha, Vector x, Vector y)`	`y = alphaA^Tx + y`
`Matrix`	`transpose()`	Transposes the matrix in-place.
`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, mult, 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, transMult, 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
  - BandMatrix
```
public BandMatrix(int n,
                  int kl,
                  int ku)
```
    Constructor for BandMatrix
    
    Parameters:
    
    n - Size of the matrix. Since the matrix must be square, this equals both the number of rows and columns
    
    kl - Number of bands above the main diagonal (superdiagonals)
    
    ku - Number of bands below the main diagonal (subdiagonals)
  - BandMatrix
```
public BandMatrix(Matrix A,
                  int kl,
                  int ku)
```
    Constructor for BandMatrix
    
    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
    
    kl - Number of bands above the main diagonal (superdiagonals)
    
    ku - Number of bands below the main diagonal (subdiagonals)
  - BandMatrix
```
public BandMatrix(Matrix A,
                  int kl,
                  int ku,
                  boolean deep)
```
    Constructor for BandMatrix
    
    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
    
    kl - Number of bands above the main diagonal (superdiagonals)
    
    ku - Number of bands below the main diagonal (subdiagonals)
    
    deep - True for a deep copy. For shallow copies, A must be a banded matrix
- Method Detail
  - copy
```
public BandMatrix 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 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
    
    Returns:
    
    A
  - 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
    
    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*A^T*x + y
    
    Specified by:
    
    transMultAdd in interface Matrix
    
    Overrides:
    
    transMultAdd 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
  - 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
  - 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
  - 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
  - iterator
```
public java.util.Iterator<MatrixEntry> iterator()
```
    Specified by:
    
    iterator in interface java.lang.Iterable<MatrixEntry>
    
    Overrides:
    
    iterator in class AbstractMatrix

a₁₁	a₁₂
a₂₁	a₂₂	a₂₃
a₃₁	a₃₂	a₃₃	a₃₄
	a₄₂	a₄₃	a₄₄	a₄₅
		a₅₃	a₅₄	a₅₅

Class BandMatrix

Nested Class Summary

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

Field Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Constructor Detail

BandMatrix

BandMatrix

BandMatrix

Method Detail

copy

zero

multAdd

transMultAdd

solve

solve

transpose

getData

add

set

get

numSubDiagonals

numSuperDiagonals

set

iterator