Class SelectedDenseObjectMatrix2D

java.lang.Object

cern.colt.PersistentObject

cern.colt.matrix.impl.AbstractMatrix

cern.colt.matrix.impl.AbstractMatrix2D

cern.colt.matrix.ObjectMatrix2D

cern.colt.matrix.impl.SelectedDenseObjectMatrix2D

All Implemented Interfaces:

Serializable, Cloneable

class SelectedDenseObjectMatrix2D
extends ObjectMatrix2D

Selection view on dense 2-d matrices holding Object elements. First see the package summary and javadoc tree view to get the broad picture.

Implementation:

Objects of this class are typically constructed via viewIndexes methods on some source matrix. The interface introduced in abstract super classes defines everything a user can do. From a user point of view there is nothing special about this class; it presents the same functionality with the same signatures and semantics as its abstract superclass(es) while introducing no additional functionality. Thus, this class need not be visible to users. By the way, the same principle applies to concrete DenseXXX and SparseXXX classes: they presents the same functionality with the same signatures and semantics as abstract superclass(es) while introducing no additional functionality. Thus, they need not be visible to users, either. Factory methods could hide all these concrete types.

This class uses no delegation. Its instances point directly to the data. Cell addressing overhead is 1 additional int addition and 2 additional array index accesses per get/set.

Note that this implementation is not synchronized.

Memory requirements:

memory [bytes] = 4*(rowIndexes.length+columnIndexes.length). Thus, an index view with 1000 x 1000 indexes additionally uses 8 KB.

Time complexity:

Depends on the parent view holding cells.

Version:

1.0, 09/24/99

Field Summary

Fields

Modifier and Type	Field	Description
protected int[]	columnOffsets
protected Object[]	elements	The elements of this matrix.
protected int	offset	The offset.
protected int[]	rowOffsets	The offsets of the visible cells of this matrix.

Fields inherited from class AbstractMatrix2D

columns, columnStride, columnZero, rows, rowStride, rowZero

Fields inherited from class AbstractMatrix

isNoView

Fields inherited from class PersistentObject

serialVersionUID

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SelectedDenseObjectMatrix2D(int rows, int columns, Object[] elements, int rowZero, int columnZero, int rowStride, int columnStride, int[] rowOffsets, int[] columnOffsets, int offset)	Constructs a matrix view with the given parameters.
protected	SelectedDenseObjectMatrix2D(Object[] elements, int[] rowOffsets, int[] columnOffsets, int offset)	Constructs a matrix view with the given parameters.

Method Summary

Modifier and Type	Method	Description
protected int	_columnOffset(int absRank)	Returns the position of the given absolute rank within the (virtual or non-virtual) internal 1-dimensional array.
protected int	_rowOffset(int absRank)	Returns the position of the given absolute rank within the (virtual or non-virtual) internal 1-dimensional array.
Object	getQuick(int row, int column)	Returns the matrix cell value at coordinate [row,column].
protected boolean	haveSharedCellsRaw(ObjectMatrix2D other)	Returns true if both matrices share common cells.
protected int	index(int row, int column)	Returns the position of the given coordinate within the (virtual or non-virtual) internal 1-dimensional array.
ObjectMatrix2D	like(int rows, int columns)	Construct and returns a new empty matrix of the same dynamic type as the receiver, having the specified number of rows and columns.
ObjectMatrix1D	like1D(int size)	Construct and returns a new 1-d matrix of the corresponding dynamic type, entirelly independent of the receiver.
protected ObjectMatrix1D	like1D(int size, int zero, int stride)	Construct and returns a new 1-d matrix of the corresponding dynamic type, sharing the same cells.
void	setQuick(int row, int column, Object value)	Sets the matrix cell at coordinate [row,column] to the specified value.
protected void	setUp(int rows, int columns)	Sets up a matrix with a given number of rows and columns.
protected AbstractMatrix2D	vDice()	Self modifying version of viewDice().
ObjectMatrix1D	viewColumn(int column)	Constructs and returns a new slice view representing the rows of the given column.
ObjectMatrix1D	viewRow(int row)	Constructs and returns a new slice view representing the columns of the given row.
protected ObjectMatrix2D	viewSelectionLike(int[] rowOffsets, int[] columnOffsets)	Construct and returns a new selection view.

Methods inherited from class ObjectMatrix2D

aggregate, aggregate, assign, assign, assign, assign, assign, cardinality, copy, equals, equals, get, getContent, getNonZeros, haveSharedCells, like, set, toArray, toString, view, viewColumnFlip, viewDice, viewPart, viewRowFlip, viewSelection, viewSelection, viewSorted, viewStrides

Methods inherited from class AbstractMatrix2D

_columnRank, _rowRank, checkBox, checkColumn, checkColumnIndexes, checkRow, checkRowIndexes, checkShape, checkShape, columns, rows, setUp, size, toStringShort, vColumnFlip, vPart, vRowFlip, vStrides

Methods inherited from class AbstractMatrix

ensureCapacity, isView, trimToSize

Methods inherited from class PersistentObject

clone

Methods inherited from class Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

elements

protected Object[] elements

The elements of this matrix.

rowOffsets

protected int[] rowOffsets

The offsets of the visible cells of this matrix.

columnOffsets

protected int[] columnOffsets

offset

protected int offset

The offset.

Constructor Details

SelectedDenseObjectMatrix2D

protected SelectedDenseObjectMatrix2D(Object[] elements,
 int[] rowOffsets,
 int[] columnOffsets,
 int offset)

Constructs a matrix view with the given parameters.

Parameters:

elements - the cells.

rowOffsets - The row offsets of the cells that shall be visible.

columnOffsets - The column offsets of the cells that shall be visible.

offset -

SelectedDenseObjectMatrix2D

protected SelectedDenseObjectMatrix2D(int rows,
 int columns,
 Object[] elements,
 int rowZero,
 int columnZero,
 int rowStride,
 int columnStride,
 int[] rowOffsets,
 int[] columnOffsets,
 int offset)

Constructs a matrix view with the given parameters.

Parameters:

rows - the number of rows the matrix shall have.

columns - the number of columns the matrix shall have.

elements - the cells.

rowZero - the position of the first element.

columnZero - the position of the first element.

rowStride - the number of elements between two rows, i.e. index(i+1,j)-index(i,j).

columnStride - the number of elements between two columns, i.e. index(i,j+1)-index(i,j).

rowOffsets - The row offsets of the cells that shall be visible.

columnOffsets - The column offsets of the cells that shall be visible.

offset -

Method Details

_columnOffset

protected int _columnOffset(int absRank)

Returns the position of the given absolute rank within the (virtual or non-virtual) internal 1-dimensional array. Default implementation. Override, if necessary.

Overrides:

_columnOffset in class AbstractMatrix2D

Parameters:

rank - the absolute rank of the element.

Returns:

the position.

_rowOffset

protected int _rowOffset(int absRank)

Returns the position of the given absolute rank within the (virtual or non-virtual) internal 1-dimensional array. Default implementation. Override, if necessary.

Overrides:

_rowOffset in class AbstractMatrix2D

Parameters:

rank - the absolute rank of the element.

Returns:

the position.

getQuick

public Object getQuick(int row,
 int column)

Returns the matrix cell value at coordinate [row,column].

Provided with invalid parameters this method may return invalid objects without throwing any exception. You should only use this method when you are absolutely sure that the coordinate is within bounds. Precondition (unchecked): 0 <= column < columns() invalid input: '&'invalid input: '&' 0 <= row < rows().

Specified by:

getQuick in class ObjectMatrix2D

Parameters:

row - the index of the row-coordinate.

column - the index of the column-coordinate.

Returns:

the value at the specified coordinate.

haveSharedCellsRaw

protected boolean haveSharedCellsRaw(ObjectMatrix2D other)

Returns true if both matrices share common cells. More formally, returns true if other != null and at least one of the following conditions is met

• the receiver is a view of the other matrix
• the other matrix is a view of the receiver
• this == other

Overrides:

haveSharedCellsRaw in class ObjectMatrix2D

index

protected int index(int row,
 int column)

Returns the position of the given coordinate within the (virtual or non-virtual) internal 1-dimensional array.

Overrides:

index in class AbstractMatrix2D

Parameters:

row - the index of the row-coordinate.

column - the index of the column-coordinate.

like

public ObjectMatrix2D like(int rows,
 int columns)

Construct and returns a new empty matrix of the same dynamic type as the receiver, having the specified number of rows and columns. For example, if the receiver is an instance of type DenseObjectMatrix2D the new matrix must also be of type DenseObjectMatrix2D, if the receiver is an instance of type SparseObjectMatrix2D the new matrix must also be of type SparseObjectMatrix2D, etc. In general, the new matrix should have internal parametrization as similar as possible.

Specified by:

like in class ObjectMatrix2D

Parameters:

rows - the number of rows the matrix shall have.

columns - the number of columns the matrix shall have.

Returns:

a new empty matrix of the same dynamic type.

like1D

public ObjectMatrix1D like1D(int size)

Construct and returns a new 1-d matrix of the corresponding dynamic type, entirelly independent of the receiver. For example, if the receiver is an instance of type DenseObjectMatrix2D the new matrix must be of type DenseObjectMatrix1D, if the receiver is an instance of type SparseObjectMatrix2D the new matrix must be of type SparseObjectMatrix1D, etc.

Specified by:

like1D in class ObjectMatrix2D

Parameters:

size - the number of cells the matrix shall have.

Returns:

a new matrix of the corresponding dynamic type.

like1D

protected ObjectMatrix1D like1D(int size,
 int zero,
 int stride)

Construct and returns a new 1-d matrix of the corresponding dynamic type, sharing the same cells. For example, if the receiver is an instance of type DenseObjectMatrix2D the new matrix must be of type DenseObjectMatrix1D, if the receiver is an instance of type SparseObjectMatrix2D the new matrix must be of type SparseObjectMatrix1D, etc.

Specified by:

like1D in class ObjectMatrix2D

Parameters:

size - the number of cells the matrix shall have.

zero - the index of the first element.

stride - the number of indexes between any two elements, i.e. index(i+1)-index(i).

Returns:

a new matrix of the corresponding dynamic type.

setQuick

public void setQuick(int row,
 int column,
 Object value)

Sets the matrix cell at coordinate [row,column] to the specified value.

Provided with invalid parameters this method may access illegal indexes without throwing any exception. You should only use this method when you are absolutely sure that the coordinate is within bounds. Precondition (unchecked): 0 <= column < columns() invalid input: '&'invalid input: '&' 0 <= row < rows().

Specified by:

setQuick in class ObjectMatrix2D

Parameters:

row - the index of the row-coordinate.

column - the index of the column-coordinate.

value - the value to be filled into the specified cell.

setUp

protected void setUp(int rows,
 int columns)

Sets up a matrix with a given number of rows and columns.

Overrides:

setUp in class AbstractMatrix2D

Parameters:

rows - the number of rows the matrix shall have.

columns - the number of columns the matrix shall have.

Throws:

IllegalArgumentException - if (Object)columns*rows > Integer.MAX_VALUE.

vDice

protected AbstractMatrix2D vDice()

Self modifying version of viewDice().

Overrides:

vDice in class AbstractMatrix2D

viewColumn

public ObjectMatrix1D viewColumn(int column)

Constructs and returns a new slice view representing the rows of the given column. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa. To obtain a slice view on subranges, construct a sub-ranging view (viewPart(...)), then apply this method to the sub-range view.

Example:

2 x 3 matrix: 1, 2, 3 4, 5, 6

viewColumn(0) ==>

Matrix1D of size 2: 1, 4

Overrides:

viewColumn in class ObjectMatrix2D

Parameters:

column - the column to fix.

the - column to fix.

Returns:

a new slice view.

Throws:

IllegalArgumentException - if column invalid input: '<' 0 || column >= columns().

See Also:

• viewRow(int)

viewRow

public ObjectMatrix1D viewRow(int row)

Constructs and returns a new slice view representing the columns of the given row. The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa. To obtain a slice view on subranges, construct a sub-ranging view (viewPart(...)), then apply this method to the sub-range view.

Example:

2 x 3 matrix: 1, 2, 3 4, 5, 6

viewRow(0) ==>

Matrix1D of size 3: 1, 2, 3

Overrides:

viewRow in class ObjectMatrix2D

Parameters:

row - the row to fix.

the - row to fix.

Returns:

a new slice view.

Throws:

IndexOutOfBoundsException - if row invalid input: '<' 0 || row >= rows().

See Also:

• viewColumn(int)

viewSelectionLike

protected ObjectMatrix2D viewSelectionLike(int[] rowOffsets,
 int[] columnOffsets)

Construct and returns a new selection view.

Specified by:

viewSelectionLike in class ObjectMatrix2D

Parameters:

rowOffsets - the offsets of the visible elements.

columnOffsets - the offsets of the visible elements.

Returns:

a new view.