org.apache.mahout.math
Class DenseMatrix

java.lang.Object
  extended by org.apache.mahout.math.AbstractMatrix
      extended by org.apache.mahout.math.DenseMatrix
All Implemented Interfaces:
Cloneable, Iterable<MatrixSlice>, Matrix, VectorIterable

public class DenseMatrix
extends AbstractMatrix

Matrix of doubles implemented using a 2-d array


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.mahout.math.AbstractMatrix
AbstractMatrix.TransposeViewVector
 
Field Summary
 
Fields inherited from class org.apache.mahout.math.AbstractMatrix
COL, columnLabelBindings, columns, ROW, rowLabelBindings, rows
 
Constructor Summary
DenseMatrix(double[][] values)
          Construct a matrix from the given values
DenseMatrix(double[][] values, boolean shallowCopy)
          Construct a matrix from the given values
DenseMatrix(int rows, int columns)
          Constructs an empty matrix of the given size.
 
Method Summary
 Matrix assign(DenseMatrix matrix)
           
 Matrix assign(double value)
          Assign the value to all elements of the receiver
 Matrix assignColumn(int column, Vector other)
          Assign the other vector values to the column of the receiver
 Matrix assignRow(int row, Vector other)
          Assign the other vector values to the row of the receiver
 Matrix clone()
          Return a copy of the recipient
 double getQuick(int row, int column)
          Return the value at the given indexes, without checking bounds
 Matrix like()
          Return an empty matrix of the same underlying class as the receiver
 Matrix like(int rows, int columns)
          Returns an empty matrix of the same underlying class as the receiver and of the specified size.
 void setQuick(int row, int column, double value)
          Set the value at the given index, without checking bounds
 Matrix viewPart(int[] offset, int[] size)
          Return a view into part of a matrix.
 Matrix viewPart(int rowOffset, int rowsRequested, int columnOffset, int columnsRequested)
          Return a view into part of a matrix.
 Vector viewRow(int row)
          Returns a view of a row.
 
Methods inherited from class org.apache.mahout.math.AbstractMatrix
aggregate, aggregateColumns, aggregateRows, asFormatString, assign, assign, assign, assign, columnSize, determinant, divide, get, get, getColumnLabelBindings, getNumNondefaultElements, getRowLabelBindings, iterateAll, iterator, minus, numCols, numRows, numSlices, plus, plus, rowSize, set, set, set, set, set, set, setColumnLabelBindings, setRowLabelBindings, times, times, times, timesSquared, toString, transpose, viewColumn, viewDiagonal, zSum
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

DenseMatrix

public DenseMatrix(double[][] values)
Construct a matrix from the given values

Parameters:
values - a double[][]

DenseMatrix

public DenseMatrix(double[][] values,
                   boolean shallowCopy)
Construct a matrix from the given values

Parameters:
values - a double[][]
shallowCopy - directly use the supplied array?

DenseMatrix

public DenseMatrix(int rows,
                   int columns)
Constructs an empty matrix of the given size.

Parameters:
rows - The number of rows in the result.
columns - The number of columns in the result.
Method Detail

clone

public Matrix clone()
Description copied from interface: Matrix
Return a copy of the recipient

Specified by:
clone in interface Matrix
Overrides:
clone in class AbstractMatrix
Returns:
a new Matrix

getQuick

public double getQuick(int row,
                       int column)
Description copied from interface: Matrix
Return the value at the given indexes, without checking bounds

Parameters:
row - an int row index
column - an int column index
Returns:
the double at the index

like

public Matrix like()
Description copied from interface: Matrix
Return an empty matrix of the same underlying class as the receiver

Returns:
a Matrix

like

public Matrix like(int rows,
                   int columns)
Description copied from interface: Matrix
Returns an empty matrix of the same underlying class as the receiver and of the specified size.

Parameters:
rows - the int number of rows
columns - the int number of columns

setQuick

public void setQuick(int row,
                     int column,
                     double value)
Description copied from interface: Matrix
Set the value at the given index, without checking bounds

Parameters:
row - an int row index into the receiver
column - an int column index into the receiver
value - a double value to set

viewPart

public Matrix viewPart(int[] offset,
                       int[] size)
Description copied from interface: Matrix
Return a view into part of a matrix. Changes to the view will change the original matrix.

Specified by:
viewPart in interface Matrix
Overrides:
viewPart in class AbstractMatrix
Parameters:
offset - an int[2] offset into the receiver
size - the int[2] size of the desired result
Returns:
a matrix that shares storage with part of the original matrix.

viewPart

public Matrix viewPart(int rowOffset,
                       int rowsRequested,
                       int columnOffset,
                       int columnsRequested)
Description copied from interface: Matrix
Return a view into part of a matrix. Changes to the view will change the original matrix.

Specified by:
viewPart in interface Matrix
Overrides:
viewPart in class AbstractMatrix
Parameters:
rowOffset - The first row of the view
rowsRequested - The number of rows in the view
columnOffset - The first column in the view
columnsRequested - The number of columns in the view
Returns:
a matrix that shares storage with part of the original matrix.

assign

public Matrix assign(double value)
Description copied from interface: Matrix
Assign the value to all elements of the receiver

Specified by:
assign in interface Matrix
Overrides:
assign in class AbstractMatrix
Parameters:
value - a double value
Returns:
the modified receiver

assign

public Matrix assign(DenseMatrix matrix)

assignColumn

public Matrix assignColumn(int column,
                           Vector other)
Description copied from interface: Matrix
Assign the other vector values to the column of the receiver

Parameters:
column - the int row to assign
other - a Vector
Returns:
the modified receiver

assignRow

public Matrix assignRow(int row,
                        Vector other)
Description copied from interface: Matrix
Assign the other vector values to the row of the receiver

Parameters:
row - the int row to assign
other - a Vector
Returns:
the modified receiver

viewRow

public Vector viewRow(int row)
Description copied from class: AbstractMatrix
Returns a view of a row. Changes to the view will affect the original.

Specified by:
viewRow in interface Matrix
Overrides:
viewRow in class AbstractMatrix
Parameters:
row - Which row to return.
Returns:
A vector that references the desired row.


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