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); } }
serialVersionUID
Constructor and Description |
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DenseObjectMatrix2D(int rows,
int columns)
Constructs a matrix with a given number of rows and columns.
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DenseObjectMatrix2D(Object[][] values)
Constructs a matrix with a copy of the given values.
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Modifier and Type | Method and Description |
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ObjectMatrix2D |
assign(Object[][] values)
Sets all cells to the state specified by values.
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ObjectMatrix2D |
assign(ObjectFunction function)
Assigns the result of a function to each cell; x[row,col] = function(x[row,col]).
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ObjectMatrix2D |
assign(ObjectMatrix2D source)
Replaces all cell values of the receiver with the values of another matrix.
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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]).
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Object |
getQuick(int row,
int column)
Returns the matrix cell value at coordinate [row,column].
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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.
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ObjectMatrix1D |
like1D(int size)
Construct and returns a new 1-d matrix of the corresponding dynamic type, entirelly independent of the receiver.
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void |
setQuick(int row,
int column,
Object value)
Sets the matrix cell at coordinate [row,column] to the specified value.
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aggregate, aggregate, assign, cardinality, copy, equals, equals, get, getNonZeros, like, set, toArray, toString, viewColumn, viewColumnFlip, viewDice, viewPart, viewRow, viewRowFlip, viewSelection, viewSelection, viewSorted, viewStrides
checkShape, checkShape, columns, rows, size, toStringShort
ensureCapacity, trimToSize
clone
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.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 ObjectMatrix2D
values
- 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 ObjectMatrix2D
function
- a function object taking as argument the current cell's value.Functions
public ObjectMatrix2D assign(ObjectMatrix2D source)
assign
in class ObjectMatrix2D
source
- 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 ObjectMatrix2D
y
- 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()Functions
public 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 ObjectMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.public ObjectMatrix2D like(int rows, int columns)
like
in class ObjectMatrix2D
rows
- 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 ObjectMatrix2D
size
- the number of cells the matrix shall have.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 ObjectMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.value
- the value to be filled into the specified cell.Jas4pp 1.5 © Java Analysis Studio for Particle Physics