org.apache.commons.math3.linear

Class OpenMapRealMatrix

java.lang.Object

org.apache.commons.math3.linear.RealLinearOperator

org.apache.commons.math3.linear.AbstractRealMatrix

org.apache.commons.math3.linear.OpenMapRealMatrix

All Implemented Interfaces:

java.io.Serializable, AnyMatrix, RealMatrix, SparseRealMatrix

public class OpenMapRealMatrix
extends AbstractRealMatrix
implements SparseRealMatrix, java.io.Serializable

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

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private int	columns Number of columns of the matrix.
private OpenIntToDoubleHashMap	entries Storage for (sparse) matrix elements.
private int	rows Number of rows of the matrix.
private static long	serialVersionUID Serializable version identifier.

Constructor Summary

Constructors

Constructor and Description
OpenMapRealMatrix(int rowDimension, int columnDimension) Build a sparse matrix with the supplied row and column dimensions.
OpenMapRealMatrix(OpenMapRealMatrix matrix) Build a matrix by copying another one.

Method Summary

Methods

Modifier and Type	Method and Description
OpenMapRealMatrix	add(OpenMapRealMatrix m) Compute the sum of this matrix and m.
void	addToEntry(int row, int column, double increment) Adds (in place) the specified value to the specified entry of this matrix.
private int	computeKey(int row, int column) Compute the key to access a matrix element
OpenMapRealMatrix	copy() Returns a (deep) copy of this.
OpenMapRealMatrix	createMatrix(int rowDimension, int columnDimension) Create a new RealMatrix of the same type as the instance with the supplied row and column dimensions.
int	getColumnDimension() Returns the number of columns of this matrix.
double	getEntry(int row, int column) Get the entry in the specified row and column.
int	getRowDimension() Returns the number of rows of this matrix.
OpenMapRealMatrix	multiply(OpenMapRealMatrix m) Postmultiply this matrix by m.
RealMatrix	multiply(RealMatrix m) Returns the result of postmultiplying this by m.
void	multiplyEntry(int row, int column, double factor) Multiplies (in place) the specified entry of this matrix by the specified value.
void	setEntry(int row, int column, double value) Set the entry in the specified row and column.
OpenMapRealMatrix	subtract(OpenMapRealMatrix m) Subtract m from this matrix.
OpenMapRealMatrix	subtract(RealMatrix m) Returns this minus m.

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

add, copySubMatrix, copySubMatrix, equals, getColumn, getColumnMatrix, getColumnVector, getData, getFrobeniusNorm, getNorm, getRow, getRowMatrix, getRowVector, getSubMatrix, getSubMatrix, getTrace, hashCode, isSquare, operate, operate, power, preMultiply, preMultiply, preMultiply, scalarAdd, scalarMultiply, setColumn, setColumnMatrix, setColumnVector, setRow, setRowMatrix, setRowVector, setSubMatrix, toString, transpose, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder

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

isTransposable, operateTranspose

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.math3.linear.RealMatrix

add, copySubMatrix, copySubMatrix, getColumn, getColumnMatrix, getColumnVector, getData, getFrobeniusNorm, getNorm, getRow, getRowMatrix, getRowVector, getSubMatrix, getSubMatrix, getTrace, operate, operate, power, preMultiply, preMultiply, preMultiply, scalarAdd, scalarMultiply, setColumn, setColumnMatrix, setColumnVector, setRow, setRowMatrix, setRowVector, setSubMatrix, transpose, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder

Methods inherited from interface org.apache.commons.math3.linear.AnyMatrix

isSquare

Field Detail

serialVersionUID

private static final long serialVersionUID

Serializable version identifier.

See Also:

Constant Field Values

rows

private final int rows

Number of rows of the matrix.

columns

private final int columns

Number of columns of the matrix.

entries

private final OpenIntToDoubleHashMap entries

Storage for (sparse) matrix elements.

Constructor Detail

OpenMapRealMatrix

public OpenMapRealMatrix(int rowDimension,
                 int columnDimension)
                  throws NotStrictlyPositiveException,
                         NumberIsTooLargeException

Build a sparse matrix with the supplied row and column dimensions.

Parameters:

rowDimension - Number of rows of the matrix.

columnDimension - Number of columns of the matrix.

Throws:

NotStrictlyPositiveException - if row or column dimension is not positive.

NumberIsTooLargeException - if the total number of entries of the matrix is larger than Integer.MAX_VALUE.

OpenMapRealMatrix

public OpenMapRealMatrix(OpenMapRealMatrix matrix)

Build a matrix by copying another one.

Parameters:

matrix - matrix to copy.

Method Detail

copy

public OpenMapRealMatrix copy()

Returns a (deep) copy of this.

Specified by:

copy in interface RealMatrix

Specified by:

copy in class AbstractRealMatrix

Returns:

matrix copy

createMatrix

public OpenMapRealMatrix createMatrix(int rowDimension,
                             int columnDimension)
                               throws NotStrictlyPositiveException,
                                      NumberIsTooLargeException

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

Specified by:

createMatrix in interface RealMatrix

Specified by:

createMatrix in class AbstractRealMatrix

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

Throws:

NumberIsTooLargeException - if the total number of entries of the matrix is larger than Integer.MAX_VALUE.

NotStrictlyPositiveException - if row or column dimension is not positive.

getColumnDimension

public int getColumnDimension()

Returns the number of columns of this matrix.

Specified by:

getColumnDimension in interface AnyMatrix

Specified by:

getColumnDimension in class AbstractRealMatrix

Returns:

the number of columns.

add

public OpenMapRealMatrix add(OpenMapRealMatrix m)
                      throws MatrixDimensionMismatchException

Compute the sum of this matrix and m.

Parameters:

m - Matrix to be added.

Returns:

this + m.

Throws:

MatrixDimensionMismatchException - if m is not the same size as this.

subtract

public OpenMapRealMatrix subtract(RealMatrix m)
                           throws MatrixDimensionMismatchException

Returns this minus m.

Specified by:

subtract in interface RealMatrix

Overrides:

subtract in class AbstractRealMatrix

Parameters:

m - matrix to be subtracted

Returns:

this - m

Throws:

MatrixDimensionMismatchException - if m is not the same size as this.

subtract

public OpenMapRealMatrix subtract(OpenMapRealMatrix m)
                           throws MatrixDimensionMismatchException

Subtract m from this matrix.

Parameters:

m - Matrix to be subtracted.

Returns:

this - m.

Throws:

MatrixDimensionMismatchException - if m is not the same size as this.

multiply

public RealMatrix multiply(RealMatrix m)
                    throws DimensionMismatchException,
                           NumberIsTooLargeException

Returns the result of postmultiplying this by m.

Specified by:

multiply in interface RealMatrix

Overrides:

multiply in class AbstractRealMatrix

Parameters:

m - matrix to postmultiply by

Returns:

this * m

Throws:

NumberIsTooLargeException - if m is an OpenMapRealMatrix, and the total number of entries of the product is larger than Integer.MAX_VALUE.

DimensionMismatchException - if columnDimension(this) != rowDimension(m)

multiply

public OpenMapRealMatrix multiply(OpenMapRealMatrix m)
                           throws DimensionMismatchException,
                                  NumberIsTooLargeException

Postmultiply this matrix by m.

Parameters:

m - Matrix to postmultiply by.

Returns:

this * m.

Throws:

DimensionMismatchException - if the number of rows of m differ from the number of columns of this matrix.

NumberIsTooLargeException - if the total number of entries of the product is larger than Integer.MAX_VALUE.

getEntry

public double getEntry(int row,
              int column)
                throws OutOfRangeException

Get the entry in the specified row and column. Row and column indices start at 0.

Specified by:

getEntry in interface RealMatrix

Specified by:

getEntry in class AbstractRealMatrix

Parameters:

row - Row index of entry to be fetched.

column - Column index of entry to be fetched.

Returns:

the matrix entry at (row, column).

Throws:

OutOfRangeException - if the row or column index is not valid.

getRowDimension

public int getRowDimension()

Returns the number of rows of this matrix.

Specified by:

getRowDimension in interface AnyMatrix

Specified by:

getRowDimension in class AbstractRealMatrix

Returns:

the number of rows.

setEntry

public void setEntry(int row,
            int column,
            double value)
              throws OutOfRangeException

Set the entry in the specified row and column. Row and column indices start at 0.

Specified by:

setEntry in interface RealMatrix

Specified by:

setEntry in class AbstractRealMatrix

Parameters:

row - Row index of entry to be set.

column - Column index of entry to be set.

value - the new value of the entry.

Throws:

OutOfRangeException - if the row or column index is not valid

addToEntry

public void addToEntry(int row,
              int column,
              double increment)
                throws OutOfRangeException

Adds (in place) the specified value to the specified entry of this matrix. Row and column indices start at 0.

Specified by:

addToEntry in interface RealMatrix

Overrides:

addToEntry in class AbstractRealMatrix

Parameters:

row - Row index of the entry to be modified.

column - Column index of the entry to be modified.

increment - value to add to the matrix entry.

Throws:

OutOfRangeException - if the row or column index is not valid.

multiplyEntry

public void multiplyEntry(int row,
                 int column,
                 double factor)
                   throws OutOfRangeException

Multiplies (in place) the specified entry of this matrix by the specified value. Row and column indices start at 0.

Specified by:

multiplyEntry in interface RealMatrix

Overrides:

multiplyEntry in class AbstractRealMatrix

Parameters:

row - Row index of the entry to be modified.

column - Column index of the entry to be modified.

factor - Multiplication factor for the matrix entry.

Throws:

OutOfRangeException - if the row or column index is not valid.

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:

key within the map to access the matrix element