Package org.apache.commons.math3.linear

Class SparseFieldMatrix<T extends FieldElement<T>>

java.lang.Object

org.apache.commons.math3.linear.AbstractFieldMatrix<T>

org.apache.commons.math3.linear.SparseFieldMatrix<T>

Type Parameters:

T - the type of the field elements

All Implemented Interfaces:

AnyMatrix, FieldMatrix<T>

public class SparseFieldMatrix<T extends FieldElement<T>>
extends AbstractFieldMatrix<T>

Sparse matrix implementation based on an open addressed map.

Caveat: This implementation assumes that, for any x, the equality x * 0d == 0d holds. But it is is not true for NaN. Moreover, zero entries will lose their sign. Some operations (that involve NaN and/or infinities) may thus give incorrect results.

Since:

2.0

Field Summary

Fields

Modifier and Type	Field	Description
private int	columns	Column dimension.
private OpenIntToFieldHashMap<T>	entries	Storage for (sparse) matrix elements.
private int	rows	Row dimension.

Constructor Summary

Constructors

Constructor	Description
SparseFieldMatrix(Field<T> field)	Create a matrix with no data.
SparseFieldMatrix(Field<T> field, int rowDimension, int columnDimension)	Create a new SparseFieldMatrix with the supplied row and column dimensions.
SparseFieldMatrix(FieldMatrix<T> other)	Generic copy constructor.
SparseFieldMatrix(SparseFieldMatrix<T> other)	Copy constructor.

Method Summary

Modifier and Type	Method	Description
void	addToEntry(int row, int column, T increment)	Change an entry in the specified row and column.
private int	computeKey(int row, int column)	Compute the key to access a matrix element.
FieldMatrix<T>	copy()	Make a (deep) copy of this.
FieldMatrix<T>	createMatrix(int rowDimension, int columnDimension)	Create a new FieldMatrix of the same type as the instance with the supplied row and column dimensions.
int	getColumnDimension()	Returns the number of columns in the matrix.
T	getEntry(int row, int column)	Returns the entry in the specified row and column.
int	getRowDimension()	Returns the number of rows in the matrix.
void	multiplyEntry(int row, int column, T factor)	Change an entry in the specified row and column.
void	setEntry(int row, int column, T value)	Set the entry in the specified row and column.

Methods inherited from class org.apache.commons.math3.linear.AbstractFieldMatrix

add, buildArray, buildArray, checkAdditionCompatible, checkColumnIndex, checkMultiplicationCompatible, checkRowIndex, checkSubMatrixIndex, checkSubMatrixIndex, checkSubtractionCompatible, copySubMatrix, copySubMatrix, equals, extractField, extractField, getColumn, getColumnMatrix, getColumnVector, getData, getField, getRow, getRowMatrix, getRowVector, getSubMatrix, getSubMatrix, getTrace, hashCode, isSquare, multiply, operate, operate, power, preMultiply, preMultiply, preMultiply, scalarAdd, scalarMultiply, setColumn, setColumnMatrix, setColumnVector, setRow, setRowMatrix, setRowVector, setSubMatrix, subtract, toString, transpose, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

entries

private final OpenIntToFieldHashMap<T extends FieldElement<T>> entries

Storage for (sparse) matrix elements.

rows

private final int rows

Row dimension.

columns

private final int columns

Column dimension.

Constructor Detail

SparseFieldMatrix

public SparseFieldMatrix(Field<T> field)

Create a matrix with no data.

Parameters:

field - Field to which the elements belong.

SparseFieldMatrix

public SparseFieldMatrix(Field<T> field,
                         int rowDimension,
                         int columnDimension)

Create a new SparseFieldMatrix with the supplied row and column dimensions.

Parameters:

field - Field to which the elements belong.

rowDimension - Number of rows in the new matrix.

columnDimension - Number of columns in the new matrix.

Throws:

NotStrictlyPositiveException - if row or column dimension is not positive.

SparseFieldMatrix

public SparseFieldMatrix(SparseFieldMatrix<T> other)

Copy constructor.

Parameters:

other - Instance to copy.

SparseFieldMatrix

public SparseFieldMatrix(FieldMatrix<T> other)

Generic copy constructor.

Parameters:

other - Instance to copy.

Method Detail

addToEntry

public void addToEntry(int row,
                       int column,
                       T increment)

Change an entry in the specified row and column.

Specified by:

addToEntry in interface FieldMatrix<T extends FieldElement<T>>

Specified by:

addToEntry in class AbstractFieldMatrix<T extends FieldElement<T>>

Parameters:

row - Row location of entry to be set.

column - Column location of entry to be set.

increment - Value to add to the current matrix entry in (row, column).

copy

public FieldMatrix<T> copy()

Make a (deep) copy of this.

Specified by:

copy in interface FieldMatrix<T extends FieldElement<T>>

Specified by:

copy in class AbstractFieldMatrix<T extends FieldElement<T>>

Returns:

a copy of this matrix.

createMatrix

public FieldMatrix<T> createMatrix(int rowDimension,
                                   int columnDimension)

Create a new FieldMatrix of the same type as the instance with the supplied row and column dimensions.

Specified by:

createMatrix in interface FieldMatrix<T extends FieldElement<T>>

Specified by:

createMatrix in class AbstractFieldMatrix<T extends FieldElement<T>>

Parameters:

rowDimension - the number of rows in the new matrix

columnDimension - the number of columns in the new matrix

Returns:

a new matrix of the same type as the instance

getColumnDimension

public int getColumnDimension()

Returns the number of columns in the matrix.

Specified by:

getColumnDimension in interface AnyMatrix

Specified by:

getColumnDimension in class AbstractFieldMatrix<T extends FieldElement<T>>

Returns:

columnDimension

getEntry

public T getEntry(int row,
                  int column)

Returns the entry in the specified row and column.

Specified by:

getEntry in interface FieldMatrix<T extends FieldElement<T>>

Specified by:

getEntry in class AbstractFieldMatrix<T extends FieldElement<T>>

Parameters:

row - row location of entry to be fetched

column - column location of entry to be fetched

Returns:

matrix entry in row,column

getRowDimension

public int getRowDimension()

Returns the number of rows in the matrix.

Specified by:

getRowDimension in interface AnyMatrix

Specified by:

getRowDimension in class AbstractFieldMatrix<T extends FieldElement<T>>

Returns:

rowDimension

multiplyEntry

public void multiplyEntry(int row,
                          int column,
                          T factor)

Change an entry in the specified row and column.

Specified by:

multiplyEntry in interface FieldMatrix<T extends FieldElement<T>>

Specified by:

multiplyEntry in class AbstractFieldMatrix<T extends FieldElement<T>>

Parameters:

row - Row location of entry to be set.

column - Column location of entry to be set.

factor - Multiplication factor for the current matrix entry in (row,column)

setEntry

public void setEntry(int row,
                     int column,
                     T value)

Set the entry in the specified row and column.

Specified by:

setEntry in interface FieldMatrix<T extends FieldElement<T>>

Specified by:

setEntry in class AbstractFieldMatrix<T extends FieldElement<T>>

Parameters:

row - row location of entry to be set

column - column location of entry to be set

value - matrix entry to be set in row,column

computeKey

private int computeKey(int row,
                       int column)

Compute the key to access a matrix element.

Parameters:

row - Row index of the matrix element.

column - Column index of the matrix element.

Returns:

the key within the map to access the matrix element.