jsat.linear

Class TransposeView

java.lang.Object

jsat.linear.Matrix

jsat.linear.GenericMatrix

jsat.linear.TransposeView

All Implemented Interfaces:

Serializable, Cloneable

public class TransposeView
extends GenericMatrix

This class provides a free view of the transpose of a matrix. This is done by accessing the matrix elements in swapped order. This has a serious performance impact. If the base matrix storage is row major order, then accessing the TransposeView in column major order will provide the best performance.

Author:

Edward Raff

See Also:

Serialized Form

Field Summary

Fields inherited from class jsat.linear.GenericMatrix

NB2

Constructor Summary

Constructors

Constructor and Description
TransposeView(Matrix base)

Method Summary

Modifier and Type	Method and Description
void	changeSize(int newRows, int newCols) This method alters the size of a matrix, either adding or subtracting rows from the internal structure of the matrix.
int	cols() Returns the number of columns stored in this matrix
double	get(int i, int j) Returns the value stored at at the matrix position Ai,j
Vec	getColumnView(int j) Obtains a vector that is backed by this, at very little memory cost.
protected Matrix	getMatrixOfSameType(int rows, int cols) Creates a new matrix of the same type
Vec	getRowView(int r) Obtains a vector that is backed by this, at very little memory cost.
boolean	isSparce() Returns true if the matrix is sparse, false otherwise
int	rows() Returns the number of rows stored in this matrix
void	set(int i, int j, double value) Sets the value stored at at the matrix position Ai,j

Methods inherited from class jsat.linear.GenericMatrix

clone, lup, lup, multiply, multiply, multiply, multiplyTranspose, multiplyTranspose, mutableAdd, mutableAdd, mutableAdd, mutableAdd, mutableMultiply, mutableMultiply, mutableTranspose, qr, qr, swapRows, transpose, transposeMultiply, transposeMultiply, transposeMultiply, zeroOut

Methods inherited from class jsat.linear.Matrix

add, add, add, add, canBeMutated, canMultiply, copyTo, diag, diagMult, diagMult, equals, equals, eye, getColumn, getRow, increment, isSquare, isSymmetric, isSymmetric, multiply, multiply, multiply, multiply, multiply, multiplyTranspose, multiplyTranspose, mutableAdd, mutableAdd, mutableSubtract, mutableSubtract, mutableSubtract, mutableSubtract, mutableSubtract, mutableSubtract, nnz, OuterProductUpdate, OuterProductUpdate, pascal, random, sameDimensions, subtract, subtract, subtract, subtract, toString, transpose, transposeMultiply, transposeMultiply, transposeMultiply, updateRow

Methods inherited from class java.lang.Object

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

Constructor Detail

TransposeView

public TransposeView(Matrix base)

Method Detail

getColumnView

public Vec getColumnView(int j)

Description copied from class: Matrix

Obtains a vector that is backed by this, at very little memory cost. Mutations to this vector will alter the values stored in the matrix, and vice versa.

Overrides:

getColumnView in class Matrix

Parameters:

j - the column to obtain a view of

Returns:

a vector backed by the specified row of the matrix

getRowView

public Vec getRowView(int r)

Description copied from class: Matrix

Obtains a vector that is backed by this, at very little memory cost. Mutations to this vector will alter the values stored in the matrix, and vice versa.

Overrides:

getRowView in class Matrix

Parameters:

r - the row to obtain a view of

Returns:

a vector backed by the specified row of the matrix

getMatrixOfSameType

protected Matrix getMatrixOfSameType(int rows,
                                     int cols)

Description copied from class: GenericMatrix

Creates a new matrix of the same type

Specified by:

getMatrixOfSameType in class GenericMatrix

Parameters:

rows - the number of rows for the matrix to have

cols - the number of columns for the matrix to have

Returns:

the empty all zero new matrix

get

public double get(int i,
                  int j)

Description copied from class: Matrix

Returns the value stored at at the matrix position A_i,j

Specified by:

get in class Matrix

Parameters:

i - the row, starting from 0

j - the column, starting from 0

Returns:

the value at A_i,j

set

public void set(int i,
                int j,
                double value)

Description copied from class: Matrix

Sets the value stored at at the matrix position A_i,j

Specified by:

set in class Matrix

Parameters:

i - the row, starting from 0

j - the column, starting from 0

value - the value to place at A_i,j

rows

public int rows()

Description copied from class: Matrix

Returns the number of rows stored in this matrix

Specified by:

rows in class Matrix

Returns:

the number of rows stored in this matrix

cols

public int cols()

Description copied from class: Matrix

Returns the number of columns stored in this matrix

Specified by:

cols in class Matrix

Returns:

the number of columns stored in this matrix

isSparce

public boolean isSparce()

Description copied from class: Matrix

Returns true if the matrix is sparse, false otherwise

Specified by:

isSparce in class Matrix

Returns:

true if the matrix is sparse, false otherwise

changeSize

public void changeSize(int newRows,
                       int newCols)

Description copied from class: Matrix

This method alters the size of a matrix, either adding or subtracting rows from the internal structure of the matrix. Every resize call may cause a new allocation internally, and should not be called for excessive changing of a matrix. All added rows/ columns will have values of zero. If a row / column is removed, it is always the bottom/right most row / column removed. Values of the removed rows / columns will be lost.

Specified by:

changeSize in class Matrix

Parameters:

newRows - the new number of rows, must be positive

newCols - the new number of columns, must be positive.