public class DenseObjectMatrix2D extends ObjectMatrix2D
Implementation:
Internally holds one single contigous one-dimensional array, addressed in row major. Note that this implementation is not synchronized.
Memory requirements:
memory [bytes] = 8*rows()*columns(). Thus, a 1000*1000 matrix uses 8 MB.
Time complexity:
O(1) (i.e. constant time) for the basic operations get, getQuick, set, setQuick and size,
Cells are internally addressed in row-major. Applications demanding utmost speed can exploit this fact. Setting/getting values in a loop row-by-row is quicker than column-by-column. Thus
for (int row=0; row < rows; row++) {
for (int column=0; column < columns; column++) {
matrix.setQuick(row,column,someValue);
}
}
is quicker than
for (int column=0; column < columns; column++) {
for (int row=0; row < rows; row++) {
matrix.setQuick(row,column,someValue);
}
}
| Modifier and Type | Field and Description |
|---|---|
protected Object[] |
elements
The elements of this matrix.
|
columns, columnStride, columnZero, rows, rowStride, rowZeroisNoViewserialVersionUID| Modifier | Constructor and Description |
|---|---|
|
DenseObjectMatrix2D(int rows,
int columns)
Constructs a matrix with a given number of rows and columns.
|
protected |
DenseObjectMatrix2D(int rows,
int columns,
Object[] elements,
int rowZero,
int columnZero,
int rowStride,
int columnStride)
Constructs a view with the given parameters.
|
|
DenseObjectMatrix2D(Object[][] values)
Constructs a matrix with a copy of the given values.
|
| Modifier and Type | Method and Description |
|---|---|
ObjectMatrix2D |
assign(Object[][] values)
Sets all cells to the state specified by values.
|
ObjectMatrix2D |
assign(ObjectFunction function)
Assigns the result of a function to each cell; x[row,col] = function(x[row,col]).
|
ObjectMatrix2D |
assign(ObjectMatrix2D source)
Replaces all cell values of the receiver with the values of another matrix.
|
ObjectMatrix2D |
assign(ObjectMatrix2D y,
ObjectObjectFunction function)
Assigns the result of a function to each cell; x[row,col] = function(x[row,col],y[row,col]).
|
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 ObjectMatrix2D |
viewSelectionLike(int[] rowOffsets,
int[] columnOffsets)
Construct and returns a new selection view.
|
aggregate, aggregate, assign, cardinality, copy, equals, equals, get, getContent, getNonZeros, haveSharedCells, like, set, toArray, toString, view, viewColumn, viewColumnFlip, viewDice, viewPart, viewRow, viewRowFlip, viewSelection, viewSelection, viewSorted, viewStrides_columnOffset, _columnRank, _rowOffset, _rowRank, checkBox, checkColumn, checkColumnIndexes, checkRow, checkRowIndexes, checkShape, checkShape, columns, rows, setUp, setUp, size, toStringShort, vColumnFlip, vDice, vPart, vRowFlip, vStridesensureCapacity, isView, trimToSizecloneprotected Object[] elements
public DenseObjectMatrix2D(Object[][] values)
The values are copied. So subsequent changes in values are not reflected in the matrix, and vice-versa.
values - The values to be filled into the new matrix.IllegalArgumentException - if for any 1 <= row < values.length: values[row].length != values[row-1].length.public DenseObjectMatrix2D(int rows,
int columns)
rows - the number of rows the matrix shall have.columns - the number of columns the matrix shall have.IllegalArgumentException - if rows<0 || columns<0 || (Object)columns*rows > Integer.MAX_VALUE.protected DenseObjectMatrix2D(int rows,
int columns,
Object[] elements,
int rowZero,
int columnZero,
int rowStride,
int columnStride)
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).IllegalArgumentException - if rows<0 || columns<0 || (Object)columns*rows > Integer.MAX_VALUE or flip's are illegal.public ObjectMatrix2D assign(Object[][] values)
The values are copied. So subsequent changes in values are not reflected in the matrix, and vice-versa.
assign in class ObjectMatrix2Dvalues - the values to be filled into the cells.IllegalArgumentException - if values.length != rows() || for any 0 <= row < rows(): values[row].length != columns().public ObjectMatrix2D assign(ObjectFunction function)
Example:
matrix = 2 x 2 matrix 0.5 1.5 2.5 3.5 // change each cell to its sine matrix.assign(cern.jet.math.Functions.sin); --> 2 x 2 matrix 0.479426 0.997495 0.598472 -0.350783For further examples, see the package doc.
assign in class ObjectMatrix2Dfunction - a function object taking as argument the current cell's value.Functionspublic ObjectMatrix2D assign(ObjectMatrix2D source)
assign in class ObjectMatrix2Dsource - the source matrix to copy from (may be identical to the receiver).IllegalArgumentException - if columns() != source.columns() || rows() != source.rows()public ObjectMatrix2D assign(ObjectMatrix2D y, ObjectObjectFunction function)
Example:
// assign x[row,col] = x[row,col]y[row,col] m1 = 2 x 2 matrix 0 1 2 3 m2 = 2 x 2 matrix 0 2 4 6 m1.assign(m2, cern.jet.math.Functions.pow); --> m1 == 2 x 2 matrix 1 1 16 729For further examples, see the package doc.
assign in class ObjectMatrix2Dy - the secondary matrix to operate on.function - a function object taking as first argument the current cell's value of this,
and as second argument the current cell's value of y,IllegalArgumentException - if columns() != other.columns() || rows() != other.rows()Functionspublic Object getQuick(int row, int 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() && 0 <= row < rows().
getQuick in class ObjectMatrix2Drow - the index of the row-coordinate.column - the index of the column-coordinate.protected boolean haveSharedCellsRaw(ObjectMatrix2D other)
haveSharedCellsRaw in class ObjectMatrix2Dprotected int index(int row,
int column)
index in class AbstractMatrix2Drow - the index of the row-coordinate.column - the index of the column-coordinate.public ObjectMatrix2D like(int rows, int columns)
like in class ObjectMatrix2Drows - the number of rows the matrix shall have.columns - the number of columns the matrix shall have.public ObjectMatrix1D like1D(int size)
like1D in class ObjectMatrix2Dsize - the number of cells the matrix shall have.protected ObjectMatrix1D like1D(int size, int zero, int stride)
like1D in class ObjectMatrix2Dsize - 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).public void setQuick(int row,
int column,
Object 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() && 0 <= row < rows().
setQuick in class ObjectMatrix2Drow - the index of the row-coordinate.column - the index of the column-coordinate.value - the value to be filled into the specified cell.protected ObjectMatrix2D viewSelectionLike(int[] rowOffsets, int[] columnOffsets)
viewSelectionLike in class ObjectMatrix2DrowOffsets - the offsets of the visible elements.columnOffsets - the offsets of the visible elements.Copyright © 2006–2019 SYSTAP, LLC DBA Blazegraph. All rights reserved.